Živilė ŽIGAITĖ

Uppsala University, Department of Organismal Biology, Subdepartment of Evolution and Development, Forskare

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Isotopic and elemental proxies to palaeobiology and palaeoenvironment.
Dental biomineral: evolution of earliest vertebrate hard tissues, fossil and modern bioapatite properties.
Shark teeth as model archives of isotopic clues to biology and environment.
Supervisors: L'Ecole Doctorale SMRE: Sciences de la Matière, du Rayonnement et de l'Environnement : University of Lille-1, France and Dr. Alain BLIECK

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Papers by Živilė ŽIGAITĖ

ZIGAITE et al 2013 HB-Thelodont-histology

Geochemistry of fossilised dental remains : a key to palaeobiology and palaeoenvironment

Rare earth and trace elements of fossil vertebrate bioapatite as palaeoenvironmental and sedimentological proxies

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Food web analysis across the Triassic-Jurassic transition shed new light on early dinosaur evolution and herbivore diversity

Food web analysis across the Triassic-Jurassic transition shed new light on early dinosaur evolut... more

Dental microwear texture analysis on extant and extinct sharks: Ante- or post-mortem tooth wear?

Palaeogeography, Palaeoclimatology, Palaeoecology, 2021

Abstract Sharks are apex-predators that play an important role in past and present aquatic food w... more Abstract Sharks are apex-predators that play an important role in past and present aquatic food webs. However, their diet - especially in extinct species - is often not well constrained. Dental microwear texture analysis (DMTA) has been successfully applied to reconstruct diet and feeding behaviours of different aquatic and terrestrial vertebrates. However, unlike in mammals, food-to-tooth contact in sharks is rather limited because only larger prey is manipulated before swallowing. Together with a fast tooth replacement rate, this reduces wear on individual teeth. Here, we present an explorative study of dental microwear texture on extant and extinct sharks to test whether ante-mortem wear is related to ingested diet or habitat preferences and resistant to post-mortem alteration processes. Shark teeth from 24 modern species and 12 fossil species from different localities were measured. As an additional comparison, extant shark teeth of Carcharhinus plumbeus were tumbled in sediment-water suspensions to simulate post-mortem mechanical alteration by sediment transport. Only three of the twelve extant shark species with three or more specimens had significantly different dental surface textures. Furthermore, no clear relation between food or habitat preferences and ante-mortem dental wear features was detected for this sample set. Tumbling modern shark teeth with siliciclastic sediment of four different grain size fractions led to increasing complexity of the dental surface. Fossil specimens resemble these experimentally altered shark teeth more in complexity and roughness. Thus, fossil shark teeth seem to display either very different (e.g. harder) diet-related wear or a strong degree of post-mortem alteration. Based on our restricted sample size, dental wear of shark teeth does overall not seem to simply reflect dietary differences; hence, it is difficult to use DMTA as reliable dietary reconstruction, in either extant nor extinct sharks.

Trace and rare earth element compositions of Silurian conodonts from the Vesiku Bone Bed: Histological and palaeoenvironmental implications

Palaeogeography, Palaeoclimatology, Palaeoecology, 2019

Abstract In-situ minor, trace and rare earth element (REE) compositions have been measured in con... more Abstract In-situ minor, trace and rare earth element (REE) compositions have been measured in conodonts from the lower Silurian Vesiku Bone Bed (Estonia), with the aim to visualize and to quantify conodont apatite elemental geochemistry, to evaluate compositional differences between conodont histologies, and to evaluate the use of conodont chemistry as a palaeobiological or palaeoenvironmental proxy. Tissue-selective analyses of minor, trace and rare earth element compositions of albid, hyaline, and basal tissues demonstrated significant chemical offsets among these histologies. The albid tissue had the lowest REE and trace element concentrations, suggesting crystallinity-determined better resilience to diagenetic alteration as documented in previous studies. Conversely, the basal tissue had highest concentrations of REEs and many trace elements, except for Sr that showed an opposite trend. The higher concentrations in albid and hyaline tissues supports the in-vivo Sr incorporation by conodont crown. Nonetheless, the obtained SN-normalized REE patterns were uniform through all the analyzed conodont taxa and different tissues, implying common diagenetic history. Absence of a Ce anomaly, and defined negative Eu anomaly indicate reducing conditions during early burial. These results validate current interpretations of the palaeoenvironmental conditions during the deposition of Vesiku Bone Bed and bolsters the use of REEs in Palaeozoic marine vertebrates as an important palaeoenvironmental proxy.

Vertebrate coprolites (fossil faeces): An underexplored Konservat-Lagerstätte

Earth-Science Reviews, 2016

Abstract Fossilized soft tissues of animals (e.g. muscles, hair and feathers) are valuable source... more Abstract Fossilized soft tissues of animals (e.g. muscles, hair and feathers) are valuable sources of palaeobiological information, but a poor preservation potential makes them undesirably scarce in the fossil record. The aim of this review is to summarize main findings, current progress and the analytical constraints of detecting fossilized soft tissues in coprolites from, mainly, freshwater and terrestrial carnivorous vertebrates. We conclude that soft-tissue inclusions in coprolites are sources of two important lines of information: the fossils can be put in a direct palaeoecological context, and characters of extinct taxa are more likely preserved in the phosphate-rich taphonomic microenvironment of coprolites than elsewhere. As a result, it is possible to unravel the deep-time origins of host-parasite relations, to understand ancient trophic food webs and detect new soft-tissue characters of different animal groups. Examples of the latter include muscle tissues from a tyrannosaurid prey, tapeworm eggs (including a developing embryo) in a Permian shark coprolite, as well as hair from multituberculates and, probably, from stem-mammals (Therapsids). Additionally, the use of coprolites in an archaeological context is briefly reviewed with focus on key aspects that may become implemented in studies of pre-Quaternary specimens as well. In summary, there is a wide range of information that can be extracted from coprolites, which has not yet been fully explored in palaeontological studies.

Palaeoenvironments revealed from rare earth element systematics in vertebrate bioapatite from the Lower Devonian of Svalbard

Canadian Journal of Earth Sciences, 2016

In situ rare-earth element (REE) compositions have been measured in early vertebrate microremains... more In situ rare-earth element (REE) compositions have been measured in early vertebrate microremains from the Lower Devonian basin of Andrée Land (Svalbard), with the aim of obtaining information about their early depositional environment and potential reworking. Vertebrate microremains with different histology were used for the analyses, sourced from two different localities of marginal marine to freshwater sediments from geographically distant parts of the Grey Hœk Formation (Skamdalen and Tavlefjellet members). We selected thelodont and undescribed ?chondrichthyan scales, which allowed us to define potential taxonomic, histological, and taphonomic variables of the REE uptake. Results showed REE concentrations to be relatively uniform within the scales of each taxon, but apparent discrepancies were visible between the studied localities and separate taxa. The compilation of REE abundance patterns as well as REE ratios have revealed that thelodont and ?chondrichthyan originating from ...

A new thelodont from Lower Silurian of Tuva and north-west Mongolia

Silurian of Central Europe

Field courses in Arctic Geology at UNIS (Svalbard, Spitsbergen)

Romantika ir kelioniø ilgesys bûdingas kiekvienam þmogui, ypaè geologui, besistengianèiam pro-fes... more Romantika ir kelioniø ilgesys bûdingas kiekvienam þmogui, ypaè geologui, besistengianèiam pro-fesiná þingeidumà suderinti su malonumu. Tuo naudojosi visø kartø Lietuvos geologai. Galimybae pa-þinti ne tik Europos, bet ir egzotiðkø mums ðaliø geologijà, jø buitá, skurdà bei prabangà turi ir jau-nosios kartos Lietuvos geologai. Svarbiausia, to siekti ne vien norais, bet ir darbais. Ðiame þurnalo numeryje spausdiname Vilniaus universiteto geologës doktorantës Þivilës Þigaitës, jau keleri metai sëk-mingai dirbanèios paleoichtiologijos srityje, straipsná. Ji sëkmingai bendradarbiauja su Kinijos ir Pran-cûzijos universitetais, praeitais metais laimëjo konkursà dalyvauti lauko seminare Ðpitsbergene, kur dirbo, mokësi ir nuo lokiø gynësi ðautuvu Þivilë Þigaitë, Vilniaus universitetas ARKTIES GEOLOGIJOS LAUKO KURSAI ÖPITSBERGENE Ðpitsbergenas (oland. rantyti kalnai) tai di-dþiausia Svalbardo archipelago sala Arkties van-denyne, pusiaukelëje tarp ðiauriausio Europos þe-myno kraðto ir Ðiaur...

Vertebrate Microfossils as Tool in Stratigraphy: A Study of the Lower Devonian Andrée Land Group, Spitsbergen

We have studied vertebrate microremains from the Lower to Middle Devonian of the Andrée Land Grou... more We have studied vertebrate microremains from the Lower to Middle Devonian of the Andrée Land Group, comprising the Wood Bay and Grey Hoek formations. We have defined two new thelodont assemblages, which represent different depositional phases during the late Early to early Middle Devonian formation of the Andrée Land Group. The definition of these two new thelodont assemblages allows us to precisely establish the relative ages of the Lower–Middle Devonian strata. Rare earth element (REE) abundances were measured in a number of thelodont and chondrichthyan microfossil dental tissue biominerals, using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS). The evaluation of fossil preservation level was performed using semiquantitative spot-geochemistry analyses on finely polished thelodont scale thin-sections using Energy Dispersive X-ray Spectroscopy (EDS), and Electron Backscattering Diffractometry (EBSD) was applied to detect recrystallization. Stable oxygen isoto...

ZIGAITE et al 2013 GFF Spitsbergen Thelodonts

Look Inside Get Access Find out how to access preview-only content Vertebrate Microfossils as Tools in Stratigraphy: A Study of the Lower Devonian Andrée Land Group, Spitsbergen

Rare earth elements (REEs) in vertebrate microremains from the upper Pridoli Ohesaare beds of Saaremaa Island, Estonia: geochemical clues to palaeoenvironment c

Estonian Journal of Earth Sciences, 2015

Rare earth element (REE) compositions of Nostolepis sp. scales, spines, plates and tesserae from ... more Rare earth element (REE) compositions of Nostolepis sp. scales, spines, plates and tesserae from Ohesaare bone beds were measured by in situ microsampling using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The obtained REE concentrations, normalized to Post-Archean Australian Shale concentrations, were evaluated using basic geochemical calculations and quantifications. The REE compositions were nearly identical across all the morphotypes and histologies of Nostolepis microremains, showing flat REE patterns with slight depletion in heavy REEs. There was no visible enrichment in middle REEs, indicating good geochemical preservation of bioapatite and absence of any pronounced fractionated REE incorporation during later stages of diagenesis. The shale-normalized (La/Yb) SN and (La/Sm) SN REE ratio compilations indicated adsorption as the dominating REE uptake mechanism across all datapoints. The absence of well-defined Ce anomaly suggested oxic palaeoseawater conditions, which agrees with the existing interpretations of the Ohesaare sequence as high-energy shoal and regressive open ocean sedimentary environments.

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Palaeoenvironmental signatures revealed from rare earth element (REE) compositions of vertebrate microremains of the Vesiku Bone Bed (Homerian, Wenlock), Saaremaa Island, Estonia

Estonian Journal of Earth Sciences, 2015

Rare earth elements (REEs) have been analysed from fossil vertebrate microremains (thelodont scal... more Rare earth elements (REEs) have been analysed from fossil vertebrate microremains (thelodont scales) from the Vesiku Bone Bed, Saaremaa, Estonia, using in situ microsampling by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Well-preserved scales of three species of the genus Thelodus (T. carinatus, T. laevis and Thelodus sp.) show very uniform REE patterns with slightly lower overall REE concentrations in enameloid than in dentine, with enrichment in middle REEs, depletion in heavy REEs and pronounced negative europium anomaly, but no cerium anomaly. The results of this study suggest a similar diagenetic history and possibly contemporaneous habitats for all three Thelodus species, as well as possible suboxic to anoxic conditions of the bottom and pore waters during the formation of the Vesiku Bone Bed.

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An overview of the Silurian system of Central Europe

New vertebrate assemblages from the Andrée Land Group, Spitsbergen, and their biostratigraphic significance

The Lower and Middle Devonian successions of Spitsbergen provide excellent examples of vertebrate... more The Lower and Middle Devonian successions of Spitsbergen provide excellent examples of vertebrate biostratigraphy applied to sedimentary basin analysis. A number of previous works on the Red Bay Group (Lochkovian, Lower Devonian) made a notable study of the earliest Devonian vertebrate record, and their use in biostratigraphy. Our current study concerns the Lower to Middle Devonian of the Andree Land Group, which comprises the Wood Bay Formation, spanning from Pragian to Emsian in age, and the Grey Hoek Formation, representing the Eifelian. It consists of thick layers of terrigenous sediments, the stratigraphy is largely based on the lithofacies.Two new thelodont assemblages are considered to represent different depostional phases of the late Lower - early Middle Devonian of the Andree Land Group. The first, older assemblage comprises turiinid, talivaliid, and furcacaudid thelodonts, and identifies the lower Wood Bay Formation. The second, younger assemblage is prevailed by the talivaliid thelodont Amaltheolepis winsnesi, and is characteristic for the upper Wood Bay Fm., as well as the lower Grey Hoek Fm. The recognition of these two new thelodont assemblages allows us to precise the relative age of the Lower – Middle Devonian strata.

Paléobiogéographie des vertébrés du Paléozoïque inférieur et moyen: données et interprétations récentes

Paleobiogeographie des vertebres du Paleozoique inferieur et moyen : donnees et interpretations r... more

Do fossil vertebrate biominerals hold the key to the Palaeozoic climate?

ABSTRACT Fossil vertebrate hard tissues -teeth and dermoskeleton -are considered among the most g... more ABSTRACT Fossil vertebrate hard tissues -teeth and dermoskeleton -are considered among the most geochemically stable biominerals, and therefore are widely used for palaeoenvironmental and palaeoclimatic reconstructions. Elemental and isotopic compositions of fossil dental tissues may provide unique palaeoenvironmental information, ranging from the diet and trophic positions on a food chain, to the palaeosalinity and water temperatures of ancient seas. However, the post-mortem alteration and re-crystallisation of fossil hard tissues may hamper these interpretations. Chemical composition and isotopic equilibrium of the biomineral change readily at any time from the earliest dia-genesis to the final laboratory acid treatment during the fossil preparation. This is why particular attention shall be given to the preservation of fossil tissues, evaluating carefully the level of possible alteration in the primary geo-chemical composition. Pre-evaluation of fossil preservation can be made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections using Energy Dispersive X-ray Spectroscopy (EDS), and help to preview the chemical composition of biomineral. The Electron Backscatter Diffractometry (EBSD) is use-ful to examine the cristallinity and possible structural alterations. In addition, rare earth element (REE) abundances can be measured in situ within the fine fossil tissues (such as enamel) using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS), giving evidence on the selective geochemical resilience between sep-arate vertebrate hard tissues. Therefore, in order to decipher the geochemical signal correctly, the evaluation of preservation is a necessary starting point to any further studies of fossil biomineral geochemistry.