Invertebrate Paleontology

This map folio should be referenced as:
Scotese, C.R., 2013. Map Folio 70 Early Devonian (Emsian, 402.3 Ma), PALEOMAP PaleoAtlas for ArcGIS, volume 4, Late Paleozoic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL.

Introduction
These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the oneused by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

RESUMEN Se registra por primera vez la presencia de un opérculo de gastrópodo fósil de la familia Turbinidae, quizá correspodiente al género Petropoma, en los estratos de la Formación Quiriquina (Maastrichtiano) de Cocholgüe. Palabras clave: Paleontología, opérculo de gastrópodo, Formación Quiriquina ABSTRACT This scientific communication aims to describe and to record for the first time a fossil calcareous gastropod operculum, collected in Quiriquina Formation near Concepción (coastal central Chile) (Upper Cretaceous, Maastrichtian) probably belonging to genus Petropoma (Turbinidae)

NEOGENE AND PLEISTOCENE BRACHIOPODS OF EMILIA (NORTHERN ITALY).
This second part of the study on the brachiopods from Emilia deals with the less common species known from this region.
The first record of the genus Discinisca Dall, 1871 from the Mediterranean area is based on Pliocene specimens from the upper bathyal clays of Quattro Castella (Reggio Emilia).
A few specimens attributable to the genus Sphenarina Cooper, 1959 are described from the Middle Miocene (Langhian) of San Michele (Modena).
The morphological description of Gryphus rovasendianus (Seguenza, 1866) has been improved, based on Miocene (Langhian) specimens. Fossil material from the Serravallian of Varzi (Lombardy) and a few specimens attributed to the same species by Seguenza (1866) and Sacco (1902), were utilised for comparison.
The study of 14 specimens of Joania ? dertomutinensis (Sacco, 1902), recently collected by the authors from the type-locality of Montegibbio (Modena), enables to confirm the validity of this species. The morphological description of this taxon has been completed, since the characters of the dorsal valve were unknown.

Xiphosurids are an archaic group of aquatic chelicerate arthropods, generally known by the colloquial misnomer of ‘horseshoe crabs’. Known from marine envi- ronments as far back as the early Ordovician, horseshoe crabs are generally considered ‘living fossils’ – descendants of a bradytelic lineage exhibiting little morphological or ecological variation throughout geological time. However, xiphosurids are known from freshwater sediments in the Palaeozoic and Mesozoic; furthermore, the contention that xiphosurids show little morphological variation has never been tested empirically. Attempts to test this are hampered by the lack of a modern phylogenetic framework with which to explore different evolutionary scenarios. Here, I present a phylogenetic analysis of Xiphosurida and explore patterns of morphospace and environmental occupation of the group throughout the Phanerozoic. Xiphosurids are shown to have invaded non-marine environments indepen- dently at least five times throughout their evolutionary history, twice resulting in the radiation of major clades – bellinurines and austrolimulids – that occupied novel regions of morphospace. These clades show a convergent ecological pattern of differentiation, speciation and subse- quent extinction. Horseshoe crabs are shown to have a more dynamic and complex evolutionary history than previ- ously supposed, with the extant species representing only a fraction of the group’s past ecological and morphological diversity.

This Atlas of Devonian Paleogeographic Maps shows the changing paleogeography from the Lochkovian (413.6 Ma) to the Devono-Carboniferous Boundary (359.2 Ma).  The maps are from volume 4 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014). Absolute age assignments are from Gradstein, Ogg & Smith (2008).  An additional map showing the disposition of the three major early Devonian faunal provinces (Malvinokaffric, Appalachian, and Rhenish-Bohemian; Cocks & Torsvik, 2002; Figure 9.) has also been included.
The following maps are included in the Atlas of Devonian Paleogeographic Maps:

Map 65  Devono-Carboniferous Boundary (359.2 Ma) Transgressive Systems Track
Map 66  Late Devonian (early Famennian, 370.3 Ma) Tournasian Supersequence Boundary 
Map 67  Late Devonian (Frasnian, 379.9 Ma) Maximum Flooding Surface
Map 68  Middle Devonian (Givetian,388.2 Ma) Frasnian Supersequence Boundary
Map 69  Middle Devonian (Eifelian, 394.3 Ma) Transgressive Systems Tract
Map 70  Early Devonian (Emsian, 402.3 Ma) Maximum Flooding Surface
Map 71  Early Devonian (Pragian, 409.1 Ma) Emsian Supersequence Boundary
Map 72  Early Devonian (Lochkovian, 413.6 Ma) Lochkovian Supersequence Boundary
Extra Map – Early Devonian Biogeography

This atlas contains an “extra” map that shows the geographic distribution of three imp0ortant early Devonian biogeographic provinces: The Appalachian Province, the Rhenish-Bpohmeian Province, and the Malvino-Kaffric Province.  The Appalachian and Rhenish-Bohemian provinces were populated by warm-water brachiopod faunas the occupied the subtropics. Though they inhabited the same latitudinal zones, they were separated by the Caledonian-Acadian mountain ranges.  It is interesting to note that Appalachian faunas appear both in the Applachina Basin of the eastern U.S. and also in northern South America (Colombia and the Amazon Basin).  Similarly, the Rhenish-Bohemian faunas are found in Northern Africa, Arabia, Central Europe, and eastern Avalonia (northern France, Belgium, and southern England). The less diverse Malvino-Kaffirc province occupied cooler latitudes closer to the South Pole.

The geographic distribution of these distinct, early Devonian faunal provices provides an important clue regarding the relative positions of Laurentia (North America), Baltic and Gondwana.  Eastern North America was adjacent to northern South America (Venezuela & Colombia) and England and Central Europe were separated by a narrow ocean from northern Africa. The South Pole was located in the vicinity of southern Brazil.

This work should be cited as
Scotese,  C.R., 2014.  Atlas of Devonian Paleogeographic Maps, PALEOMAP Atlas for ArcGIS, volume 4, The Late Paleozoic, Maps 65-72, Mollweide Projection, PALEOMAP Project, Evanston, IL.

Convincingly specific homologies between Ediacarans and members of recognized animal phyla have remained elusive, thus casting a shadow of doubt over the animal affinity interpretation of Ediacaran phylogeny. Spriggina floundersi, for example, has been described as a tomopterid annelid, an arthropod, and a frondose vendobiont. Reanalysis of Spriggina demonstrates the presence of genal spines (comparable to those of fallotaspidoid and paradoxidid trilobites), a cephalic region homologous to the effaced cephalons of agraulid and skehanid trilobites, and a dual cephalic region (also seen in Parvancorina) that compares to the parts of a trilobite cephalon anterior and posterior of the facial suture. Spriggina is thus a trilobitoid ecdysozoan, a conclusion in accord with Sven Jorgen Birket-Smith's inference of an arthropod affinity for Spriggina. This result is among the first confident phylogenetic linkages between an Ediacaran and a Cambrian animal, and thus helps to demonstrate that Paleozoic animals could indeed be descended from Ediacarans. If Spriggina is a direct ancestor of trilobites, then a case can be made that Spriggina itself (or a direct descendant) served as the predator taxon that initiated the Cambrian ecotone transformation (McMenamin, M. A. S., 2003, Origin and early evolution of predators: The ecotone model and early evidence for macropredation. In: P. Kelley, M. Kowalewski and T. Hansen, eds., Predator-Prey Interactions in the Fossil Record). Such heterotrophy, however, does not preclude the possibility of photosymbiosis or other types of mixotrophy in Ediacarans with high surface area such as Marywadea and Dickinsonia.

This paper discusses the chiton fauna (Mollusca, Polyplacophora) from some deposits at Altavilla Milicia (NW Sicily) presumably older than the late Upper Pliocene. The study material consists of 550 valves from 5 samples (ORTO1-2 and KYLA1-3a) of the “Sabbie di Altavilla” Formation. This is the first comprehensive account of fossil chitons from the Pliocene of Sicily. We identified 14 species: Leptochiton cancellatus, L. algesirensis, Leptochiton sp., Hanleya hanleyi, Ischnochiton rissoi, I. anserinus, I. martinelli, Stenosemus dolii, Callochiton septemvalvis, Chiton sp., Lepidochitona caprearum, Acanthochitona fascicularis, A. crinita and Craspedochiton altavillensis. Two species (S. dolii and C. altavillensis) represent 77.3 % of the total amount of the valves. The finding of I. anserinus and I. martinelli is particularly important since these rare, scarcely known species were reported only from few Pliocene localities in Italy and Spain. Nine species are still living in the Medit...

These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the oneused by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

A set of seven atlases has been compiled for each of the principal climatic variables: Temperature (Scotese and Moore, 2014a), Atmospheric Pressure and Winds (Scotese and Moore, 2014b),  Rainfall and Runoff (Scotese and Moore, 2014c), Ocean Currents and Salinity (Scotese & Moore, 2014d), Upwelling (Scotese and Moore, 2014e), Anoxia (Scotese, 2014b), and Lithologic Indicators of Climate (Scotese, Boucot and Xu, 2014).  These atlases show the FOAM simulation results for all 18 time intervals (Figure 1).

(More discussion about the maps in this folio in the near future.)

This map folio should be referenced as:
Scotese, C.R., 2013. Map Folio 54, Early Permian (Artinskian, 280 Ma), PALEOMAP PaleoAtlas for ArcGIS, volume 4, Late Paleozoic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL.

2013.47 These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear, or plate caree map projection can also be directly “wrapped” onto a spherical projection, like the oneused by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

This map folio should be referenced as:
Scotese, C.R., 2013. Map Folio 86, Middle Cambrian, (520 Ma), PALEOMAP PaleoAtlas for ArcGIS, volume 5, Early Paleozoic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL.
Also see: Scotese,  C.R., 2014.  Atlas of Cambrian and Early Ordovician Paleogeographic Maps (Mollweide Projection), Maps 81 – 88, Volumes 5, The Early Paleozoic, PALEOMAP Atlas for ArcGIS, PALEOMAP Project, Evanston, IL, https://www.academia.edu/16785571/Atlas_of_Cambrian_and_Early_Ordovician_Paleogeographic_Maps

Introduction
These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the one used by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from eastcentral Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they encrusted the ammonite during its lifetime. If so, this implies that the soft body of the scaphite did not cover the outside surface of the aperture, leaving this area vulnerable to epizoan attachment. A total of 13 specimens of Discinisca are also present on four specimens of Cataceramus? barabini from east-central Wyoming. The brachiopods occur in crevices on the outside of the shells and may have encrusted the inoceramids after their death as the shells began to break down and delaminate, resulting from the decomposition of the organic matrix holding them together. Based on the faunal assemblages at both localities, the presence of Discinisca may indicate environments with either low oxygen levels and/or few predators or competitors.

For many astronomers, the progressive development of life has been seen as a natural occurrence given proper environmental conditions on a planet: even though such beings would not be identical to humans, there would be significant parallels. A striking contrast is seen in writings of nonphysical scientists, who have held more widely differing views. But within this diversity, reasons for differences become more apparent when we see how views about extraterrestrials can be related to the differential emphasis placed on modern evolutionary theory by scientists of various disciplines. One clue to understanding the differences between the biologists, paleontologists, and anthropologists who speculated on extraterrestrials is suggested by noting who wrote on the subject. Given the relatively small number of commentators on the topic, it seems more than coincidental that four of the major contributors to the evolutionary synthesis in the 1930s and 1940s are among them. Upon closer examination it is evident that the exobiological arguments of Theodosius Dobzhansky and George Gaylord Simpson and, less directly, of H. J. Muller and Ernst Mayr are all related to their earlier work in formulating synthetic evolution. By examining the variety of views held by nonphysical scientists, we can see that there were significant disagreements between them about evolution into the 1960s. By the mid-1980s, many believed that “higher” life, particularly intelligent life, probably occurs quite infrequently in the universe; nevertheless, some held out the possibility that convergence of intelligence could occur across worlds. Regardless of the final conclusions these scientists reached about the likely prevalence of extraterrestrial intelligence, the use of evolutionary arguments to support their positions became increasingly common.

Exceptionally preserved fossils provide crucial insights into extinct body plans and organismal evolution. Molluscs, one of the most disparate animal phyla, radiated rapidly during the early Cambrian period (approximately 535–520 million years ago (Ma)). The problematic fossil taxa Halkieria and Orthrozanclus (grouped in Sachitida) have been assigned variously to stem-group annelids, brachiopods , stem-group molluscs or stem-group aculiferans (Polyplacophora and Aplacophora), but their affinities have remained controversial owing to a lack of preserved diagnostic characters. Here we describe a new early sachitid, Calvapilosa kroegeri gen. et sp. nov. from the Fezouata biota of Morocco (Early Ordovician epoch, around 478 Ma). The new taxon is characterized by the presence of a single large anterior shell plate and polystichous radula bearing a median tooth and several lateral and uncinal teeth in more than 125 rows. Its flattened body is covered by hollow spinose sclerites, and a smooth, ventral girdle flanks an extensive mantle cavity. Phylogenetic analyses resolve C. kroegeri as a stem-group aculiferan together with other single-plated forms such as Maikhanella (Siphogonuchites) and Orthrozanclus; Halkieria is recovered closer to the aculiferan crown. These genera document the stepwise evolution of the aculiferan body plan from forms with a single, almost conchiferan-like shell through two-plated taxa such as Halkieria, to the eight-plated crown-group aculiferans. C. kroegeri therefore provides key evidence concerning the long debate about the crown molluscan affinities of sachitids. This new discovery strongly suggests that the possession of only a single calcareous shell plate and the presence of unmineralised sclerites are plesiomorphic (an ancestral trait) for the molluscan crown.

Course name: Introduction to the Paleontology and Paleoanthropology of Spain

Saint Louis University, Madrid Campus, Faculty: Science and Engineering
Semester:  Spring 2005.

Course description: This course gives an introduction into the Paleontology and Paleoanthropology of Spain. Basic principles and methods of Paleontology and Paleoanthropology will be outlined. Especially presented will be the origins of life and human beings, evolution, and extinctions. The paleontological part will concentrate on some interesting Spanish case studies (reefs of the Devonian period, swamp forests of the Carboniferous period, shallow sea of the Jurassic period, dinosaurs from the Upper Jurassic and Lower Cretaceous, and mammals and insects of the Tertiary period). In the center of the paleoanthropological part will be the famous findings of Homo antecessor and Homo heidelbergensis in the caves of Atapuerca and their importance for our knowledge about Human evolution.

Course Calendar:
Monday, Jan. 17: 1. Introduction – What are Fossils?
Wednesday, Jan. 19: 2. The Geologic Time Scale
Monday, Jan. 24, & Wednesday, Jan. 26: 3. Evolution and Taxonomy – Biology and Paleontology in Dialogue (I)
Thursday, Jan. 27: End of DROP/ADD period
Monday, Jan. 31, & Wednesday, Feb. 2: 3. Evolution and Taxonomy – Biology and Paleontology in Dialogue (II) & 4. Biogeography and Mass Extinctions (I)
Monday, Feb. 7: 4. Biogeography and Mass Extinctions (II)
Wednesday, Feb. 9: 5. From the Origins of Life to the Silurian
Monday, Feb. 14: Review & Preparation of first mid-term exam
Monday, Feb. 14: Deadline for the submission of the title of the paper
Wednesday, Feb. 16: First mid-term exam.
Monday, Feb. 21: 6. Reefs of the Devonian Period
Wednesday, Feb. 23: 7. Swamp Forests of the Carboniferous Period (I)
Monday, Feb. 28: 7. Swamp Forests of the Carboniferous Period (II) & 8. Reptiles of the Triassic Period
Wednesday, Mar. 2: 9. Life of the Shallow Sea of the Jurassic Period (I)
Saturday, Mar. 5, to Sunday, Mar. 13: SPRING BREAK
Monday, Mar. 14: 9. Life of the Shallow Sea of the Jurassic Period (II)
Wednesday, Mar. 16: 10. Dinosaurs from the Upper Jurassic and Cretaceous (I)
Monday, Mar. 21: 10. Dinosaurs from the Upper Jurassic and Cretaceous (II)
Wednesday, Mar. 23: 11. Fossils of the Tertiary Period
Thursday, Mar. 24, to Sunday, Mar. 27: Easter
Monday, Mar. 28: Review & Preparation of second mid-term exam
Wednesday, Mar. 30: Second mid-term exam
Monday, Apr. 4: Deadline for the submission of papers and PowerPoint presentations
Monday, Apr. 4, & Wednesday, Apr. 6: 12. Outline of Human evolution.
Friday, Apr. 8: Last day to drop a class and receive a grade of "W"
Monday, Apr. 11, & Wednesday, Apr. 13: 13. The Earliest Man in Spain – the Homo from Orce. & 14. Homo antecessor and Homo heidelbergensis from the Caves of Atapuerca (Prov. Burgos) (I)
Saturday, Apr. 16: Field trip to Guadalajara
Monday, Apr. 18: 14. Homo antecessor and Homo heidelbergensis from the Caves of Atapuerca (Prov. Burgos) (II)
Wednesday, Apr. 20: 15. The Humans after Homo heidelbergensis in Spain.
Monday, Apr. 25, & Wednesday, Apr. 27: Presentation of papers

The mollusc  fauna  of  the  Brabant  Loam  (Liempde Deposit,  Formation  of  Boxtel)  is  described on  the basis of a  review of  research of  the  last one hundred years. Although much research was undertaken, hardly anything of it can be traced in publications. This contribution  tries  to  fill  this gap  in our knowledge. Because  the very varying methods of  research, results are difficult to compare with each other and therefore only a review has been made with presence or absence of taxa. For the same reason, conclusions are only possible to a limited degree. Only for one location, an outcrop near Acht, do the data lend themselves for a graphical representation and an analysis of the palaeoecological developments in the section.
The associations point here to a becoming wetter with a subsequent becoming dried up of a shallow pool in an open landscape with a vegetation of grasses and herbs. Seventeen locations are know  from the Brabant Loam  from which 35 taxa are known, 29 of which could be identified to species level. The most common species are Succinea schumacheri, Anisus leucostomus auct., Succinea oblonga s.l., Pupilla muscorum, Vertigo genesii, Gyraulus rossmaessleri and Columella  columella. All associations  found  indicate moist  to wet biotopes  in an open landscape during a subarctic climate. The average number of taxa per  location  is 10 which is a normal number for mollusc associations indicative of cold non-marine conditions. The mollusc species present give no indication of a specific stratigraphical age other than that it concerns a cold period. Earlier published data show that the Brabant Loam dates from a late phase of Marine Isotope Stage 3.

La sofisticación del consumo de productos y servicios en la globalización ha ocasionado que muchas empresas contraten a otras para que les proporcionen servicios calificados de informática, telemarketing, administración y diseño gráfico que incorporarán a su producto final; los trabajadores no son contratados directamente por la empresa beneficiada, sino por otras a quienes se le subroga un contrato mercantil. Estos trabajadores pueden ubicarse en las instalaciones de la empresa contratante, en el domicilio de la empresa contratada o en ambas. Hay servicios que al no ser el objetivo principal de la empresa contratante, se subrogan a un tercero: limpieza, jardinería, transporte y vigilancia. También hay trabajadores que no dependen laboralmente de la empresa que los emplea, aunque sea ésta quien determine sus funciones y obligaciones; al no tener relación contractual directa con este tipo de trabajadores, la empresa beneficiada no les retribuye la actividad desempeñada, lo hace la empresa que los contrató a través de honorarios, comisiones o propinas. Uno de cada cinco trabajadores ocupados en México corresponde a trabajadores subcontratados como los descritos anteriormente, que por lo general son los más desprotegidos por la legislación laboral: casi la mitad de ellos carece de seguridad social y 15 por ciento no tienen contrato laboral escrito (José de Jesús González Rodríguez. (2019). La subcontratación laboral en el marco de la nueva legislación del trabajo. www.diputados.gob.mx/cesop). En este tipo de trabajadores prevalece la inestabilidad laboral, hay ausencia de representación sindical y no se cubren las prestaciones mínimas consignadas en la ley Federal de Trabajo: jornada de 48 horas semanales, aguinaldos, vacaciones, vivienda, reparto de utilidades, antigüedad laboral y acceso al sistema de salud. La subcontratación también obedece a la reducción de costos salariales, a la evasión de cuotas patronales por concepto de seguridad social y a eludir pagos fiscales: el senador Napoleón Gómez Urrutia estima que la subcontratación laboral genera un desfalco anual al erario equivalente al 2 por ciento del Producto Interno Bruto (500 mil millones de pesos) al no cubrir los empleadores sus cuotas de seguridad social y pago de impuestos (La Jornada. 9/12/19, página 24). Uno de los trabajos subcontratados es el de vigilancia, los polis realizan jornadas de 24 horas activos por 24 de descanso (o su variante 12 por 12); cada semana laboran 84 horas y la paga es de 14 pesos por hora; no hay horas extras, vacaciones, reparto de utilidad, seguridad social, capacitación, seguro de vida, aguinaldo; frecuentemente los cambian de adscripción, son penalizados por sus ausencias y su turno se duplica si así lo desea la empresa contratada. No tienen contrato escrito ni representación gremial; la empresa para quien laboran cambia frecuentemente de razón social para eludir sus compromisos laborales y fiscales y la empresa beneficiada por ese servicio niega su solidaridad laboral. Ante estas irregularidades, el grupo parlamentario de Morena en el Senado promovió una iniciativa para tutelar los derechos laborales de los trabajadores subcontratados. La propuesta de regular el trabajo subcontratado descrita fue aprobada por unanimidad en las comisiones del Senado (Trabajo y Previsión Social y Estudios Legislativos), pero por decesión del coordinador de Morena, Ricardo Monreal, se postergó su presentación al pleno. Los puntos centrales de la dicha propuesta son: acotar la subcontratación a especializaciones ajenas o accesorias a la actividad preponderante de la empresa; garantizar los derechos laborales y de seguridad social de los trabajadores y prohibir y sancionar actos simulados. La discusión y aprobación de esas reformas son necesarias para acotar los abusos laborales y el impago de cuotas de seguridad y obligaciones fiscales. es un suplemento mensual auspiciado por La Jornada de Oriente DIRECTORA GENERAL Carmen Lira Saade DIRECTOR

2013.53 These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the oneused by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

This Atlas of Cambrian and Early Ordovician Paleogeographic Maps shows the changing paleogeography from the base of the Cambrian (542 Ma) to the Early Ordovician (Arenig, 473.4 Ma).  The maps are from volume 5 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014). Absolute age assignments are from Gradstein, Ogg & Smith (2008). 

The following maps are included in the Atlas of Cambrian and Early Ordovician Paleogeographic Maps:

Map 81  Early Ordovician (Arenig, 472.4 Ma) Arenigian Supersequence Boundary
Map 82  Early Ordovician (Tremadoc, 480 Ma) Maximum Flooding Surface 
Map 83  Cambro-Ordovician Boundary (488.3 Ma) Tremadocian Supersequence Boundary
Map 84  Late Cambrian (Furongian, 494 Ma) Croixian Supersequence Boundary
Map 85  early Late Cambrian (510 Ma) Transgressive Systems Tract
Map 86  Middle Cambrian (520 Ma) Transgressive Systems Tract
Map 87  Early Cambrian (531.5 Ma) Albertan Supersequence Boundary
Map 88  Cambrian-Precambrian Boundary (542 Ma) Caerfaian Supersequence Boundary


This work should be cited as
Scotese,  C.R., 2014.  Atlas of Cambrian and Early Ordovician Paleogeographic Maps (Mollweide Projection), Maps 81-88, Volumes 5, The Early Paleozoic, PALEOMAP Atlas for ArcGIS, PALEOMAP Project, Evanston, IL.

This three-volume work provides a complete study of this well-known group of animals, dealing with every level of their biological organization, from the molecular to the zoological.
    The leech, once so prominent in the history of medicine, is again being used widely in modern hospitals, especially in microsurgery. Revival in the use of leeches coincides with recent revelations about the rich diversity of pharmacologically active peptides secreted by the leech, including the powerful anticoagulant Hirudin which was discovered in 1884. The author who has studied  leeches extensively for many years, documents for the first time the scientific and biological rationale underlying the medical use of leeches and concludes that there was a nucleus of truth behind their use in previous centuries.
    In recent years the leech has been the subject of much neurobiological research, but such research has tended to emphasize the neurophysiological aspects. This book gives an authoritative account of leech neurobiology from the biological viewpoint, with emphasis on the neuronal basis and the evolution of leech behaviour.
    The book takes up Manton's controversial thesis that insects, myriapods and onychophorans constitute a new phylum (Uniramia) unrelated to the Crustacea. He also significantly extends the argument by proposing that leeches are also allied to the Uniramia. This proposal is a major intrusion into the traditional classification of the animal kingdom, and as such is likely to gain considerable attention.
    A 'key' to the leeches of each zoogeographical region of the world and an extensive bibliography (volume 3) are included.
    The diverse and wide-ranging nature of the book should make it of interest to research workers and students in various disciplines, particularly medicine, molecular biology, neurobiology, zoology and marine biology.
    Volume 1:    0 19 857377 4,  430 pages, 170 illustrations
    Volume 2:    0 19 857622 6,  430 pages, 170 illustrations
    Volume 3:    0 19 857623 4,  240 pages

Course name: Introduction to the Paleontology and Paleoanthropology of Spain

Saint Louis University, Madrid Campus, Faculty: Science and Engineering
Semester:  Spring 2005.

Course description: This course gives an introduction into the Paleontology and Paleoanthropology of Spain. Basic principles and methods of Paleontology and Paleoanthropology will be outlined. Especially presented will be the origins of life and human beings, evolution, and extinctions. The paleontological part will concentrate on some interesting Spanish case studies (reefs of the Devonian period, swamp forests of the Carboniferous period, shallow sea of the Jurassic period, dinosaurs from the Upper Jurassic and Lower Cretaceous, and mammals and insects of the Tertiary period). In the center of the paleoanthropological part will be the famous findings of Homo antecessor and Homo heidelbergensis in the caves of Atapuerca and their importance for our knowledge about Human evolution.

Course Calendar:
Monday, Jan. 17: 1. Introduction – What are Fossils?
Wednesday, Jan. 19: 2. The Geologic Time Scale
Monday, Jan. 24, & Wednesday, Jan. 26: 3. Evolution and Taxonomy – Biology and Paleontology in Dialogue (I)
Thursday, Jan. 27: End of DROP/ADD period
Monday, Jan. 31, & Wednesday, Feb. 2: 3. Evolution and Taxonomy – Biology and Paleontology in Dialogue (II) & 4. Biogeography and Mass Extinctions (I)
Monday, Feb. 7: 4. Biogeography and Mass Extinctions (II)
Wednesday, Feb. 9: 5. From the Origins of Life to the Silurian
Monday, Feb. 14: Review & Preparation of first mid-term exam
Monday, Feb. 14: Deadline for the submission of the title of the paper
Wednesday, Feb. 16: First mid-term exam.
Monday, Feb. 21: 6. Reefs of the Devonian Period
Wednesday, Feb. 23: 7. Swamp Forests of the Carboniferous Period (I)
Monday, Feb. 28: 7. Swamp Forests of the Carboniferous Period (II) & 8. Reptiles of the Triassic Period
Wednesday, Mar. 2: 9. Life of the Shallow Sea of the Jurassic Period (I)
Saturday, Mar. 5, to Sunday, Mar. 13: SPRING BREAK
Monday, Mar. 14: 9. Life of the Shallow Sea of the Jurassic Period (II)
Wednesday, Mar. 16: 10. Dinosaurs from the Upper Jurassic and Cretaceous (I)
Monday, Mar. 21: 10. Dinosaurs from the Upper Jurassic and Cretaceous (II)
Wednesday, Mar. 23: 11. Fossils of the Tertiary Period
Thursday, Mar. 24, to Sunday, Mar. 27: Easter
Monday, Mar. 28: Review & Preparation of second mid-term exam
Wednesday, Mar. 30: Second mid-term exam
Monday, Apr. 4: Deadline for the submission of papers and PowerPoint presentations
Monday, Apr. 4, & Wednesday, Apr. 6: 12. Outline of Human evolution.
Friday, Apr. 8: Last day to drop a class and receive a grade of "W"
Monday, Apr. 11, & Wednesday, Apr. 13: 13. The Earliest Man in Spain – the Homo from Orce. & 14. Homo antecessor and Homo heidelbergensis from the Caves of Atapuerca (Prov. Burgos) (I)
Saturday, Apr. 16: Field trip to Guadalajara
Monday, Apr. 18: 14. Homo antecessor and Homo heidelbergensis from the Caves of Atapuerca (Prov. Burgos) (II)
Wednesday, Apr. 20: 15. The Humans after Homo heidelbergensis in Spain.
Monday, Apr. 25, & Wednesday, Apr. 27: Presentation of papers

2014.12 This Atlas of Middle & Late Permian and Triassic Paleogeographic Maps shows the changing paleogeography from the Middle Permian (Roadian & Wordian, 268.2 Ma) to the end of the Triassic (Rhaetian, 201.6 Ma).  The maps are from volumes 3 and 4 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014). Absolute age assignments are from Gradstein, Ogg & Smith (2008). 

The following maps are included in the Atlas of Jurassic Paleogeographic Maps:

Map 43  Late Triassic (Rhaetian, 201.6 Ma) Lowstand Systems Tract
Map 44  Late Triassic (Norian, 210 Ma) Maximum Flooding Surface 
Map 45  Late Triassic (Carnian, 222.6 Ma) Transgressive Systems Tract
Map 46  Middle Triassic (Ladinian, 232.9 Ma) Transgressive Systems Tract
Map 47  Middle Triassic (Anisian, 241.5 Ma) Lowstand Systems Tract
Map 48  Early Triassic (Induan & Olenekian, 248.5 Ma) Lowstand Systems Track
Map 49  Permo-Triassic Boundary (251 Ma) Norian Supersequence Boundary
Map 50  Late Permian (Lopingian, 255.7 Ma) Transgressive Systems Tract
Map 51  late Middle Permian (Capitanian, 263.1 Ma) Lowstand Systems Tract
Map 52  Middle Permian (Roadian & Wordian, 268.2 Ma) Maximum Flooding Surface

This work should be cited as
Scotese,  C.R., 2014.  Atlas of Middle & Late Permian and Triassic Paleogeographic Maps, maps 43 - 48 from Volume 3 of the PALEOMAP Atlas for ArcGIS (Jurassic and Triassic) and maps 49 – 52 from Volume 4 of the PALEOMAP PaleoAtlas for ArcGIS (Late Paleozoic), Mollweide Projection, PALEOMAP Project, Evanston, IL.

This map folio should be referenced as:
Scotese, C.R., 2013. Map Folio 82, Early Ordovician (Tremadoc, 480 Ma), PALEOMAP PaleoAtlas for ArcGIS, volume 5, Early Paleozoic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL.
Also see: Scotese,  C.R., 2014.  Atlas of Cambrian and Early Ordovician Paleogeographic Maps (Mollweide Projection), Maps 81 – 88, Volumes 5, The Early Paleozoic, PALEOMAP Atlas for ArcGIS, PALEOMAP Project, Evanston, IL, https://www.academia.edu/16785571/Atlas_of_Cambrian_and_Early_Ordovician_Paleogeographic_Maps

Introduction
These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the one used by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

The genus Galactochilus Sandberger has been treated as a typical fossil representative of helicoid land snails in Europe ever since its first description. Several authors have discussed the systematic relationships of the taxon, but all of them overlooked that the type species of the genus is a recent species from the Caribbean. In order to clarify their taxonomic and systematic identity, we reexamined the species formerly assigned to Galactochilus. Oligocene species, here assigned to the genus Galactochiloides Wenz, can be distinguished from Miocene representatives by differences in teleoconch surface ornamentation. For the latter we introduce the new genus Agalactochilus, with the late Miocene Helix leobersdorfensis Troll as type species. Because of the morphological and, apparently, phylogenetic distinctness of the two genera within the Helicoidea, we propose a new subfamilial taxon, the Galactochiloidini n.trib., which we tentatively rank within the Helicidae: Ariantinae.

This Atlas of Silurian and Middle-Late Ordovician Paleogeographic Maps shows the changing paleogeography from the Middle Ordovician (Darwillian, 464.5 Ma) to the Late Silurian (Ludlow & Prodoli, 419.5 Ma).  The maps are from volume 5 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014). Absolute age assignments are from Gradstein, Ogg & Smith (2008). 

The following maps are included in the Atlas of Silurian and Middle-Late Ordovician Paleogeographic Maps:

Map 73  Late Silurian (Ludlow & Pridoli, 419.5 Ma) Lochkovian Supersequence Boundary
Map 74  Middle Silurian (Wenlock, 425.6 Ma) Highstand System Tract 
Map 75  Early Silurian (late Llandovery, 432.1 Ma) Maximum Flooding Surface
Map 76  Early Silurian (early Llandovery, 439.8 Ma) Transgressive Systems Tract
Map 77  Late Ordovician (Hirnantian, 444.7 Ma) Llandoverian Supersequence Boundary
Map 78  Late Ordovician (Ashgill, 448.3 Ma) Lowstand Systems Tract & Maximum Flooding Surface
Map 79  Late Ordovician (Caradoc, 456 Ma) Maximum Flooding Surface
Map 80  Middle Ordovician (Darwillian, 464.5 Ma) Llandeilian Supersequence Boundary


This work should be cited as
Scotese,  C.R., 2014.  Atlas of Silurian and Middle-Late Ordovician Paleogeographic Maps (Mollweide Projection), Maps 73 – 80, Volumes 5, The Early Paleozoic, PALEOMAP Atlas for ArcGIS, PALEOMAP Project, Evanston, IL.

Abstract
This report describes the contents of the PALEOMAP PaleoAtlas for GPlates, describes how the maps in the PaleoAtlas were made, documents the sources of information used to make the paleogeographic maps,  and provides instructions how to plot user-defined paleodata on the paleogeographic maps using the program “PaleoDataPlotter”.  The PALEOMAP PaleloAtlas and the program (Mac OSX) can be downloaded at  http://www.earthbyte.org/paleomap-paleoatlas-for-gplates/ .

Please cite this work as:  Scotese, C.R., 2016. PALEOMAP PaleoAtlas for GPlates and the PaleoData Plotter Program, PALEOMAP Project,  http://www.earthbyte.org/paleomap-paleoatlas-for-gplates/

Part  I.  Introduction
The PALEOMAP PaleoAtlas for GPlates consists of 91 paleogeographic maps spanning the Phanerozoic and late Neoproterozoic. Table 1 lists all the time intervals that comprise the six volumes of the PALEOMAP PaleoAtlas for GPlates.  The PaleoAtlas contains one map for nearly every stage in the Phanerozoic, as well as 3 maps for the late Precambrian. The PaleoAtlas can be directly loaded into GPLates as a “Time Dependant Raster” file (see Part III, “Loading the PALEOMAP PaleoAtlas into GPlates”). A paleogeographic map is defined as a map that shows the ancient configuration of the ocean basins and continents, as well as important topographic and bathymetric features such as mountains, lowlands, shallow sea, continental shelves, and deep oceans (Figure 1, Early Cretaceous, 121.8 Ma). Ideally, a paleogeographic map would be the kind of reference map that any time traveler would like to have before embarking on a journey back through time.
Colorful paleogeographic maps may be nice to look at, but the maps become much more useful for research and teaching purposes if users can plot their own data on the maps.  In this regard, user-defined paleodata can be plotted on the paleogeographic maps in two ways: 1) using GPLates tools and procedures to import symbols and labels in a GIS-format (see GPlates Tutorial 1.1: Loading and Saving Data),  and 2) by  loading user-defined, latitude/longitude point data “text files”  using the program “PaleoDataPlotter”.  The latter method is described in the Section IV, “Plotting User-Defined Data on the Paleogeographic Reconstructions”. 
PaleoDataPlotter, which is provided with this report, creates a variety of geometric symbols  (circles, squares, triangles, stars, plus signs, crosses, small dots, and arrows) as well as short numeric labels (up to 5 digits),  that can be plotted on the paleogeographic map at user-defined latitude/longitude coordinates (Figure 2).  The PaleoDataPlotter program is ideal for plotting fossil localities, geological outcrops, as well as the locations of drill sites, wells, stratigraphic sections, or any point data set whose geographic location can be specified by modern, latitude and longitude coordinates.  The arrow symbol, which can be oriented according to a user-supplied azimuth, is particularly useful for plotting “vector” information such as:  ocean current directions, river flow, wind directions, paleomagnetic declinations, stress fields, and instantaneous plate motions. In a future version, the PaleoDataPlotter will also be able to plot text-labels at specific latitude/longitude coordinates.

These maps (rectilinear projection) are from the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2013a-f).  This is a digital atlas of plate tectonic, paleogeographic, and paleoclimatic reconstructions designed for use with the GIS software, ArcMap (ESRI).  Table 1 lists the various types of maps that comprise the PALEOMAP PaleoAtlas.  The maps included in this folio are highlighted in bold text (Table 1).
The last map in each folio is a rectilinear graticule that can be overlain on the maps to provide a geographic reference frame.  A rectilinear projection was used because it can be easily georeferenced in ArcMap and transformed into a variety of other map projections.  The rectilinear map projection can also be directly “wrapped” onto a spherical projection, like the oneused by Google Earth. A set of Google Earth paleoglobes has made from the maps in this folio. These Google Earth paleoglobes can be downloaded at: www.globalgeology.com. 
If the map you need is missing, or if there doesn’t seem to be a map folio for the exact time interval of interest, please contact me (cscotese@gmail.com). Table 2 lists all the time intervals that comprise the PALEOMAP PaleoAtlas for ArcGIS. The PaleoAtlas contains one map for every stage in the Phanerozoic, as well as 6 maps for the late Precambrian.  Eventually, Map Folios, like this one, will be published for every time interval in the PALEOMAP PaleoAtlas.  The following section is a brief description of the maps that makeup the Map Folio.

This map folio should be referenced as:
Scotese, C.R., 2013. Map Folio 57, Late Pennsylvanian (Gzhelian 301.2 Ma), PALEOMAP PaleoAtlas for ArcGIS, volume 4, Late Paleozoic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL.

The illaenid trilobite Vysocania is widely represented in the Upper Ordovician of the Czech Republic, Portugal and Spain, and is one of the most characteristic taxa in the high-latitude peri-Gondwana palaeobiogeographical region to which it is endemic. Three species of the genus that were formerly assigned to Stenopareia and Zetillaenus, from the Czech Republic and Spain respectively, are herein revised, and a new species is described from the Czech Republic. The genus Octillaenus, of which a new species is described from the Upper Ordovician of Morocco, is considered to have arisen from Vysocania through paedomorphic (neotenic) processes. The relationships between Vysocania, Octillaenus, Stenopareia and Zetillaenus are reviewed and the criteria used in the definition of these taxa discussed. Species assigned to Vysocania are V. vaneki (type-species), V. iberica, V. moraveci sp. nov. and V. panderi; species assigned to Octillaenus are O. hisingeri (type-species) and O. marocanus sp. nov. Vysocania appears for the first time in the lower Berounian (Sandbian) and has its last undoubted record in the upper Berounian (upper Katian); Octillaenus is presently restricted to the Kralodvorian (upper Katian). •

Recent description of the oral cone of Anomalocaris canadensis from the Burgess Shale (Cambrian Series 3, Stage 5) highlighted significant differences from published accounts of this iconic species, and prompts a new evaluation of its morphology as a whole. All known specimens of A. canadensis, including previously unpublished material, were examined with the aim of providing a cohesive morphological description of this stem lineage arthropod. In contrast to previous descriptions, the dorsal surface of the head is shown to be covered by a small, oval carapace in close association with paired stalked eyes, and the ventral surface bears only the triradial oral cone, with no evidence of a hypostome or an anterior sclerite. The frontal appendages reveal new details of the arthrodial membranes and a narrower cross-section in dorsal view than previously reconstructed. The posterior body region reveals a complex suite of digestive, respiratory, and locomotory characters that include a differentiated foregut and hindgut, a midgut with paired glands, gill-like setal blades, and evidence of muscle bundles and struts that presumably supported the swimming movement of the body flaps. The tail fan includes a central blade in addition to the previously described three pairs of lateral blades. Some of these structures have not been identified in other anomalocaridids, making Anomalocaris critical for understanding the functional morphology of the group as a whole and corroborating its arthropod affinities.

Exceptionally preserved fossils from the Palaeozoic era provide crucial insights into arthropod evolution, with recent discoveries bringing phylogeny and character homology into sharp focus. Integral to such studies are anomalocaridids, a clade of stem arthropods whose remarkable morphology illuminates early arthropod relationships and Cambrian ecology. Although recent work has focused on the anomalocaridid head, the nature of their trunk has been debated widely.Here we describe new anomalocaridid specimens from the Early Ordovician Fezouata Biota of Morocco, which not only show well-preserved head appendages providing key ecological data, but also elucidate the nature of anomalocaridid trunk flaps, resolving their homology with arthropod trunk limbs. The new material shows that each trunk segment bears a separate dorsal and ventral pair of flaps, with a series of setal blades attached at the base of the dorsal flaps. Comparisons with other stem lineage arthropods indicate that anomalocaridid ventral flaps are homologous with lobopodous walking limbs and the endopod of the euarthropod biramous limb, whereas the dorsal flaps and associated setal blades are homologous with the flaps of gilled lobopodians (for example, Kerygmachela kierkegaardi,  Pambdelurion whittingtoni) and exites of the ‘Cambrian biramous limb’. This evidence shows that anomalocaridids represent a stage before the fusion of exite and endopod into the ‘Cambrian biramous limb’, confirming their basal placement in the euarthropod stem, rather than in the arthropod crown or with cycloneuralian worms. Unlike other anomalocaridids, the Fezouata taxon combines head appendages convergently adapted for filter-feeding with an unprecedented body length exceeding 2m, indicating a new direction in the feeding ecology of the clade. The evolution of giant filter-feeding anomalocaridids may reflect the establishment of highly developed planktic ecosystems during the Great Ordovician Biodiversification Event.

The systematic affinities of several Palaeozoic skeletal taxa were only resolved when their soft-tissue morphology was revealed by the discovery of exceptionally preserved specimens. The conodonts provide a classic example, their tooth-like elements having been assigned to various invertebrate and vertebrate groups for more than 125 years until the discovery of their soft tissues revealed them to be crown-group vertebrates. Machaeridians, which are virtually ubiquitous as shell plates in benthic marine shelly assemblages ranging from Early Ordovician (Late Tremadoc) to Carboniferous, have proved no less enigmatic. The Machaeridia comprise three distinct families of worm-like animals, united by the possession of a dorsal skeleton of calcite plates that is rarely found articulated. Since they were first described 150 years ago machaeridians have been allied with barnacles, echinoderms, molluscs or annelids. Here we describe a new machaeridian with preserved soft parts, including parapodia and chaetae, from the Upper Tremadoc of Morocco, demonstrating the annelid affinity of the group. This discovery shows that a lineage of annelids evolved a dorsal skeleton of calcareous plates early in their history; it also resolves the affinities of a group of problematic Palaeozoic invertebrates previously known only from isolated elements and occasional skeletal assemblages.

This "flipbook", which illustrates the plate tectonic development of the continents and ocean basins during the past 750 million years, was assembled to commemorate the scientific career of Professor Rob van der Voo.  The flipbook consists of 34 plate tectonic reconstructions that map the past location of subduction zones (barbed lines), mid-ocean ridges, (dashed lines), and collision zones (marked x's). The tectonic reconstructions are based on the global plate tectonic model developed by the PALEOMAP Project. 
The latitudinal orientation of the continents is derived largely from paleomagnetic data collected by Professor van der Voo (xref).  Hot spots tracks and sea floor spreading isochrons (Seton et al., 2012) were used to constrain the longitudinal position of the continents back to  ~200 million years.  Plate tectonic reconstructions older than 200 million years are necessarily more speculative and have been derived by combining diverse lines of evidence from the tectonic histories of the continents (e.g., timing of continent-continent collisions or ages of rifting), the distribution of paleoclimatic indicators (i.e coals, tillites, salt deposits, and bauxites, see Boucot et al., 2013), and in some case, the biogeographic affinities of fossil faunas and floras.
Though a diverse data has been used to produce these reconstructions, this data, itself, is not  enough.  So much time has passed and so little direct evidence is preserved that guidance must also be sought from the "Rules of Plate Tectonics".
Plates do not move randomly but evolve in a manner that is consistent with the forces that drive them.  The principal driving forces are: slab pull, ridge push and trench rollback.  These forces shape the plates and provide important insights into how plate boundaries will evolve.  Simply said, plates will only move if they are pulled by a subducting slab or pushed by the forces exerted by a mature ridge system. The evolving plate boundaries have been drawn to follow this maxim.  It is also important to note that plate tectonics is a "catastrophic" system.  Though "slow and steady" is the general rule, once every hundred million years or so, a major plate tectonic reorganization occurs. These "plate tectonic catastrophes" most often occur when mid-ocean ridges are subducted or when major continents collide. (For a more complete listing of the "Rules of Plate Tectonics", the reader is referred to XXXXXX.
The first "continental drift" flipbook was pushed as an undergraduate research project (Scotese, 1974; 1975abc). Subsequent editions have followed (1976ab; 1978; 1979; 1980;  1990, 1991, 1997, 2004). A more complete description of the data and information that is used to produce the flipbooks can be found in Scotese (2004).  These maps could not have been produced without the GPlates plate modelling software and the tectonic data sets published by Dietmar Müller and his team at Earthbytes.
Special thanks to Maggie Geiger, and Robert and Jonathan Scotese for their help assembling this flipbook.

Time Scale
The age given next to each map represents age in millions of years.  The corresponding geological ages (Ogg et al., 2008)  are:
0    Modern World
20 Ma  Early Miocene
40 Ma  late Middle Eocene
60 Ma  Paleocene
80 Ma  Late Cretaceous - Campanian
100 Ma  Early Cretaceous - late Albian
120 Ma  Early Cretaceous - early Aptian
140 Ma  Early Cretaceous - Berriasian
160 Ma  Late Jurassic - Oxfordian
180 Ma  Early Jurassic - Toarcian
200 Ma  Triassic/Jurassic boundary
220 Ma  Late Triassic - Carnian
240 Ma  Middle Triassic - Anisian
260 Ma  Middle Permian - Capitanian
280 Ma  Early Permian - Artinskian
300 Ma  Late Pennsylvanian
320 Ma  Late Mississippian
340 Ma  Middle Mississippian
360 Ma  Devono-Carboniferous
380 Ma  Late Devonian - Frasnian
400 Ma  Early Devonian - Emsian
420 Ma  Late Silurian - Ludlow
440 Ma  Early Silurian - Llandovery
460 Ma  Middle Ordovician
480 Ma  Early Ordovician
500 Ma  Late Cambrian
520 Ma  Middle Cambrian
540 Ma  Cambrian-Precambrian
560 Ma  Neoproterozoic - lt. Ediacaran
600 Ma  Neoporterozoic - m. Ediacaran
630 Ma  Neoproterozoic - e. Ediacaran
660 Ma  Neoproterozoic - e. Ediacaran
690 Ma  Neoproterozoic - lt. Cryogenian
720 Ma  m. Cryogenian
750 Ma  m. Cryogenian


References Cited

Ogg, J., Ogg, G., and Gradstein, F.M., 2008. The Concise Geologic Time Scale, Cambridge University Press, 177 p.
Scotese, C.R. 1974. First Flip Book Images (from 35mm film from PLATO System), Unpublished.
Scotese, C.R., and Baker, D.W., 1975a. Continental drift reconstructions and animation, Journal of Geological Education, 23: 167-171.
Scotese, C.R., 1975b.  Continental Drift Flip Book, 1stedition.Chicago, Illinois. (single page version

Scotese, C.R., 1975c.  Continental Drift Flip Book, 1st edition. Chicago, Illinois. (double page version)
Scotese, C.R., 1976a. Continental
Drift “Flip Book”,  edition 1.5, Department of Geological Sciences, University of Illinois. ResearchGate  Academia
Scotese, C.R., 1976b. A continental drift “flip book", Computers & Geosciences, 2:113-116.
Scotese, C.R., and Ziegler, A.M., 1978. Paleozoic continental drift reconstructions and animation, American Geophysical Union, 1978 Spring Annual Meeting, Eos, v. 59. Issue 4, p. 263.
Scotese, C.R., 1979. Continental Drift (flip book), 2nd edition.
Scotese, C.R., Snelson, S.S., and Ross, W.C., 1980. A computer animation of continental drift, J. Geomag. Geoelectr., 32: suppl. III, 61-70.
Scotese, C.R., 1990. Atlas of Phanerozoic Plate Tectonic Reconstructions, PALEOMAP Progress 01-1090a, Department of Geology, University of Texas at Arlington, Texas, 57 pp.
Scotese, C.R., 1991. Continental Drift Flip Book, 4th edition, PALEOMAP Project, Arlington, TX, 49 pp.
Scotese, C.R., 1997.  Continental Drift Flip Book, 7th edition, PALEOMAP Project, Department of Geology, University of Texas at Arlington, Texas, 80 pp.

Scotese, 2004.
Seton et al., 2012.
Van der Voo,  R., 1993. Paleomagnetism of the Atlantic, Tethys, and Iapetus Oceans, Cambridge University Press, 411 p.

The renowned soft-bodied faunas of the Cambrian period, which
include the Burgess Shale, disappear from the fossil record in the late Middle Cambrian, after which the Palaeozoic fauna dominates. The disappearance of faunas of Burgess Shale type curtails the stratigraphic record of a number of iconic Cambrian taxa. One possible explanation for this loss is a major extinction, but more probably it reflects the absence of preservation of similar softbodied faunas in later periods. Here we report the discovery of numerous diverse soft-bodied assemblages in the Lower and
Upper Fezouata Formations (Lower Ordovician) of Morocco,
which include a range of remarkable stem-group morphologies
normally considered characteristic of the Cambrian. It is clear that biotas of Burgess Shale type persisted after the Cambrian and are preserved where suitable facies occur. The Fezouata biota provides a link between the Burgess Shale communities and the early stages of the Great Ordovician Biodiversification Event.

The discovery of the Fezouata biota in the latest Tremadocian of southeastern Morocco has significantly changed
our understanding of the early Phanerozoic radiation. The shelly fossil record shows a well-recognized pattern of macroevolutionary
stasis between the Cambrian Explosion and the Great Ordovician Biodiversification Event, but the rich soft-bodied
Fezouata biota paints a different evolutionary picture. The Fezouata assemblage includes a considerable component of
Cambrian holdovers alongside a surprising number of crown group taxa previously unknown to have evolved by the Early
Ordovician. Study of the Fezouata biota is in its early stages, and future discoveries will continue to enrich our view of the
dynamics of the early Phanerozoic radiation and of the nature of the fossil record.

A new aglaspidid arthropod, Chlupacaris dubia gen. et sp. nov., is described from the Pusgillian (lower Ashgill, Upper Ordovician) Upper Tiouririne Formation near Erfoud, southeastern Morocco. Although disarticulated, careful documenting of the tergites allows a reconstruction of the exoskeleton to be made. Although somewhat trilobite-like in appearance, the lack of facial sutures, a well-defined axis with articulating half-rings and a pygidium clearly prove Chlupacaris gen. nov. is not a trilobite. An interesting feature is the presence of a hypostome in this non-trilobite arthropod. In contrast to other aglaspidids usually considered to be carnivorous, a filter-feeding mode of life is proposed for Chlupacaris gen. nov., based on the strongly vaulted cephalon, subvertical orientation of the hypostome and less strongly vaulted trunk. Chlupacaris gen. nov. is probably most closely related to the atypical aglaspidid Tremaglaspis unite from the Tremadoc (Lower Ordovician) of the U.K., but it can also be tentatively linked to the problematic Lower Cambrian arthropods Kodymirus vagans and Kockurus grandis from the Czech Republic. The relevance and validity of previous definitions and of possibly significant characters used for identifying aglaspidids are evaluated, and as a result, a new combination of characters diagnosing Aglaspidida is proposed. Contrary to previous reports, it is suggested that aglaspidids are probably more closely related to trilobites than they are to chelicerates. This notion may be supported by the shared possession of a mineralised cuticle, a possibly similar number of cephalic appendages, and the presence of a hypostome in some forms, although this last character may alternatively be homoplastic.

Anomalocaridids, giant lightly sclerotized invertebrate predators,
occur in a number of exceptionally preserved early and middle
Cambrian (542–501 million years ago) biotas and have come to
symbolize the unfamiliar morphologies displayed by stem organisms in faunas of the Burgess Shale type. They are characterized by a pair ofanterior, segmented appendages, a circlet of plates around the mouth, and an elongate segmented trunk lacking true tergites with a pair of flexible lateral lobes per segment. Disarticulated body parts, such as the anterior appendages and oral circlet, had been assigned to a range of taxonomic groups—but the discovery of complete specimens from the middle Cambrian Burgess Shale showed that these disparate elements all belong to a single kind of animal. Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods. The anomalocaridids were the largest animals in Cambrian communities. The youngest unequivocal examples occur in the middle Cambrian Marjum Formation of Utah but an arthropod retaining some anomalocaridid characteristics is present in the Devonian of Germany. Here we report the post-Cambrian occurrence of anomalocaridids, from the Early Ordovician (488–472 million years ago) Fezouata Biota in southeastern Morocco, including specimens larger than any in Cambrian biotas. These giant animals were an important element of some marine communities for about 30 million years longer than previously realized. The Moroccan specimens confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments; these blades probably functioned as gills.