Migrations, diversifications and extinctions: the evolutionary history of crocodyliforms in Australasia

Alcheringa An Australasian Journal of Palaeontology, Journal Year: 2023, Volume and Issue: 47(4), P. 370 - 415

Published: May 22, 2023

Crocodyliform palaeontology in Australasia has a productive research record that began the late nineteenth century and continues today. In this study, we summarize current understanding on taxonomic diversity phylogenetic relationships of Australasian crocodyliforms based first-hand knowledge relevant fossil material review published literature. The currently known Crocodyliformes spans more than 113 million years, from Early Cretaceous to Holocene, largely consists body fossils discovered continental Australia. Whilst only two crocodyliform genera are recognized Australasia's Mesozoic, Cenozoic is distinguished by remarkable crocodylian crocodyliforms. By far most common crocodylians members Mekosuchinae, whose unambiguously early Eocene until Holocene. addition mekosuchines, during was also inhabited gavialoids species Crocodylus, with four extant latter being surviving Australia New Guinea. crocodylians, particularly have been topic interest palaeontologists for over decades. We performed several analyses test Mekosuchinae other extinct crocodylians. Most results our found as basal crocodyloid clade within Longirostres. However, some recovered an alternative position majority mekosuchines outside Longirostres Late Cretaceous–early Paleogene Orientalosuchina its deeply nested subclade. These suggest had origins Asia Cretaceous, arrived southeast into no later Paleocene. If hypothesis correct, then would longer be endemic since seem persisted Eocene.Jorgo Ristevski [[email protected]], School Biological Sciences, University Queensland, Brisbane, 4072, Australia; Paul M. A. Willis [[email protected]], Flinders University, Adelaide, 2100, South Australia, Adam Yates [[email protected]], Museum Central Art Gallery Northern Territory, Alice Springs, 0870, Matt White [[email protected]], Palaeoscience Research Centre, England, Armidale, 2351, Wales, Australian Age Dinosaurs Natural History, Jump-Up, Winton, 4735, Lachlan J. Hart [[email protected]], Earth Sustainability Science Biological, Environmental Sciences (BEES), Kensington, 2052, Institute, 1 William Street, Sydney, 2010, Michael D. Stein [[email protected]], Center, Gilbert Price [[email protected]], Steven W. Salisbury [[email protected]],

Language: Английский

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Osteology of Crocodylus palaeindicus from the late Miocene–Pleistocene of South Asia and the phylogenetic relationships of crocodyloids

Journal of Systematic Palaeontology, Journal Year: 2024, Volume and Issue: 22(1)

Published: March 21, 2024

Fossil crocodylian remains have been documented from India and other parts of South Asia since the mid-nineteenth century, but specimens attributed to several extinct extant species Crocodylus largely neglected in modern taxonomic treatments. Here, we present a detailed anatomical description palaeindicus, which restrict late Miocene early middle Pleistocene India. Using an autapomorphy-based approach species-level identification, regard sivalensis as junior synonym C. palaeindicus provide re-identifications all previously referred these two species. We new diagnosis for that facilitates its distinction mugger crocodile, palustris, does not unequivocally appear fossil record prior Pleistocene. The lack clear spatiotemporal overlap, coupled with otherwise lengthy ghost lineage implied by their sister-taxon relationship our phylogenetic analyses, provides tentative support either is descendant or originated via budding cladogenesis. An expanded analysis recovers African checchiai Pliocene American falconensis within Neotropical clade, supporting origin this radiation. also recover Kinyang, early–middle Kenya, crocodyline, rather than osteolaemine originally described, it potentially stratigraphically earliest known member lineage. Other notable results analyses suggest crocodyloids might North America Neogene arrival Crocodylus, Albertosuchus knudsenii, Prodiplocynodon langi 'Crocodylus' affinis recovered outside Crocodyloidea. Furthermore, demonstrate alligatoroid placement recently erected latest Cretaceous–Palaeogene East Asian clade Orientalosuchina highly labile, relationships at 'base' Crocodylia unstable.

Language: Английский

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A review of the non‐semiaquatic adaptations of extinct crocodylomorphs throughout their fossil record

The Anatomical Record, Journal Year: 2024, Volume and Issue: 308(2), P. 266 - 314

Published: Nov. 25, 2024

Abstract Crocodylomorphs constitute a clade of archosaurs that have thrived since the Mesozoic until today and survived numerous major biological crises. Contrary to historic belief, their semiaquatic extant representatives (crocodylians) are not living fossils, and, during evolutionary history, crocodylomorphs evolved live in variety environments. This review aims summarize non‐semiaquatic adaptations (i.e., either terrestrial or fully aquatic) different groups from periods, highlighting how exactly those lifestyles inferred for animals, with regard geographic temporal distribution phylogenetic relationships. The ancestral condition Crocodylomorpha seems been lifestyle, linked several morphological such as an altirostral skull, long limbs allowing erect posture specialized dentition diets based on land. However, some members this clade, thalattosuchians dyrosaurids display opposite, aquatic interestingly same type observations. Finally, new techniques inferring paleobiology extinct animals put forward last decade, appearing complementary approach traditional descriptions comparisons. Such is case paleoneuroanatomical (CT scan data), histological, geochemical studies.

Language: Английский

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Neuroanatomy of the crocodylian Tomistoma dowsoni from the Miocene of North Africa provides insights into the evolutionary history of gavialoids

Journal of Anatomy, Journal Year: 2023, Volume and Issue: 243(1), P. 1 - 22

Published: March 16, 2023

Abstract The interrelationships of the extant crocodylians Gavialis gangeticus and Tomistoma schlegelii have been historically disputed. Whereas molecular analyses indicate a sister taxon relationship between these two gavialoid species, morphological datasets typically place as outgroup to all other crocodylians. Recent morphological‐based phylogenetic begun resolve this discrepancy, recovering closest living relative ; however, several stratigraphically early fossil taxa are recovered closer than , resulting in anomalously divergence timings. As such, additional data might be required remaining discrepancies. ‘ ’ dowsoni is an extinct species from Miocene North Africa. Utilising CT scans near‐complete, referred skull, we reconstruct neuroanatomy neurosensory apparatus . Based on qualitative quantitative morphometric comparisons with crocodyliforms, characterised by intermediate morphology gavialoids, more closely resembling This mirrors results recent studies based external anatomy three gavialoids. Several neuroanatomical features appear reflect ecological and/or signals. For example, ‘simple’ their broadly similar that long narrow‐snouted (longirostrine), aquatic crocodyliforms. A dorsoventrally short, anteroposteriorly endosseous labyrinth also associated longirostry. These snout skull morphology, which themselves partly constrained ecology, exert influence has recognised birds turtles. Conversely, presence pterygoid bulla its absence could interpreted signal related Gaviali s Evaluation gavialoids will needed further test whether primarily or signal. By incorporating such previously inaccessible information into macroecological studies, can potentially constrain clade's interrelationships, well evaluate timing association evolution features. Finally, our study supports being phylogenetically indicating necessity taxonomic revision species.

Language: Английский

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Fishboneviz: Enhancing the availability of zooarchaeological fish reference collections through an open access 3D database

Australian Archaeology, Journal Year: 2024, Volume and Issue: 90(2), P. 236 - 248

Published: May 3, 2024

Fish remains are a common component of coastal and inland archaeological assemblages from Australia the Pacific Islands. Physical reference collections primary tool that researchers use to taxonomically identify fish bones but given high biodiversity fishes in this region, frequently not complete at genus- species-level. Adjunct resources, such as online photograph repositories bone illustrated technical guides, provide useful supplementary aids. However, 2D photographs illustrations offer fixed perspectives do allow for ready manipulation detailed examination specimen. Here, we introduce Fishboneviz, first open access 3D collection, which was developed reduce inequitable physical line with FAIR principles data management (findable, accessible, interoperable, reusable). A 'best-practice' methodology established facilitate fast effective segmentation (i.e. isolate regions interest elements) Computed Tomography (CT) scans. This way, elements were segmented digital viewing element. To examine effectiveness approach, image procedures applied representative sample 10 per fish: dentary, premaxilla, maxilla, articular, quadrate, hyomandibular, opercle, preopercle, last precaudal vertebra, caudal vertebra. For species within family Labridae, three pharyngeal grinding plates also segmented. These selected they represent different skeleton, variable morphologies, commonly recovered sites. date, collection contains skeletal 26 (18 families). In future, it is hoped will be further expanded by broader network interested collaborators ensure grows according changing needs research teaching communities.

Language: Английский

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Evaluation of the endocranial anatomy of the early Paleogene north African gavialoid crocodylian Argochampsa krebsi and evolutionary implications for adaptation to salinity tolerance in marine crocodyliforms

Journal of Anatomy, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Abstract Argochampsa krebsi is a gavialoid crocodylian from the early Paleogene of North Africa. Based on its recovered phylogenetic relationship with South American species, it has been inferred to have capable transoceanic dispersal, but potential anatomical correlates for marine lifestyle yet be identified. CT scans mostly complete and well‐preserved skull, we reconstruct endocranial anatomy compare that other gavialoids. We demonstrate possesses concave depressions internal surface prefrontals lacrimals, which represent osteological salt glands in unequivocally metriorhynchoid thalattosuchian crocodyliforms. The presence these suggests likely frequented pelagic environments provides additional support capability dispersal within Gavialoidea. also newly interpret Miocene north African Sutekhsuchus dowsoni , providing further saltwater tolerance was widespread possibly ancestral Gavialoidea, given they previously reported Late Cretaceous–early species Eosuchus lerichei Portugalosuchus azenhae . In addition gavialoids, as well metriorhynchids, identify gland Paleocene northwest dyrosaurid Rhabdognathus aslerensis represents another crocodyliform lineage thought dispersal. Given dyrosaurids, metriorhynchoids are distantly related lineages, evolution convergent ecological adaptation occupation environments. Nevertheless, limited evaluation across Crocodyliformes, including most extant such remains possible much more widespread.

Language: Английский

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Giant longirostrine crocodylians from the Lower Miocene of Pakistan: new material and taxonomic review

Papers in Palaeontology, Journal Year: 2025, Volume and Issue: 11(3)

Published: May 1, 2025

Abstract This study, based on previously undescribed crocodylian remains from the Lower Miocene of Bugti Hills (Balochistan, Pakistan), identifies at least three distinct species. It confirms validity species initially identified as ‘ Gavialis ’ pachyrhynchus , establishing it sister taxon to massive Rhamphosuchus crassidens . Consequently, is reclassified Additionally, Gharialis curvirostris now acknowledged a valid under new genus name Pseudogavialis closely related Another set represents third species, although poor preservation hinders precise identification. The phylogenetic relationship between Tomistoma and one most debated issues in phylogeny. Molecular analyses suggest sister‐taxa dating back Early Miocene, while morphological place base tree, diverging ‘thoracosaurs’, with Gavialoidea–Crocodyloidea split Cretaceous. inclusion newly described yields variable outcomes, highlighting sensitivity results considered. insertion Portugalosuchus azenhae found ‘thoracosaur’, aligns traditional findings, Indo‐Pakistani supports molecular hypothesis. Nevertheless, large number gavialoids ‘thoracosaurs’ makes result strongly stratigraphically incongruent. fossil significantly impacts our understanding relationships. Even when align data, persistent stratigraphic incongruence does not resolve – dilemma.

Language: Английский

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Cranial anatomy of the mekosuchine crocodylianTrilophosuchus rackhamiWillis, 1993

The Anatomical Record, Journal Year: 2022, Volume and Issue: 306(2), P. 239 - 297

Published: Aug. 13, 2022

One of the best-preserved crocodylian fossil specimens from Cenozoic Australia is holotype mekosuchine Trilophosuchus rackhami, middle Miocene (13.56 ± 0.67 Ma) Ringtail Site at Riversleigh, northwestern Queensland. Although lacking most snout, skull T. rackhami (QMF16856) has an exceptionally well-preserved cranium. Micro-CT scanning allowed for all preserved cranial bones to be digitally disarticulated, facilitating unprecedented insight into anatomy not just but any mekosuchine. was a small-bodied and one morphologically distinct mekosuchines, characterized by unique combination characteristics several which are exclusive species. Fossil material that definitively referrable species currently known solely Site. However, isolated parietal Hiatus Riversleigh demonstrates also occurred during late Oligocene (~25 Ma), extending range genus more than 10 million years. The new description reevaluation its phylogenetic relationships. Our results reaffirm placement as member Mekosuchinae within subclade Mekosuchini. In analyses, consistently found monophyletic part larger clade Longirostres. assignment subset Crocodylidae brought question, suggesting status subfamily should reconsidered.

Language: Английский

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Neuroanatomy of the mekosuchine crocodylianTrilophosuchus rackhamiWillis, 1993

Journal of Anatomy, Journal Year: 2022, Volume and Issue: 241(4), P. 981 - 1013

Published: Aug. 29, 2022

Abstract Although our knowledge on crocodylomorph palaeoneurology has experienced considerable growth in recent years, the neuroanatomy of many taxa yet to be studied. This is true for Australian taxa, where thus far only two crocodylian crocodylomorphs have had aspects their explored. Here, mekosuchine Trilophosuchus rackhami described first time, which significantly increases understanding crocodylians. The palaeoneurological description based taxon's holotype specimen (QMF16856), was subjected a μCT scan. Because exceptional preservation QMF16856, most neuroanatomical elements could digitally reconstructed and detail. Therefore, assessment presented here hitherto in‐depth study this kind an extinct crocodylomorph. brain endocast with distinctive morphology that characterized by acute dural peak over hindbrain region. While overall unique T. , it does share certain similarities notosuchian crocodyliforms Araripesuchus wegeneri Sebecus icaeorhinus . endosseous labyrinth displays typical crocodylians, although stand‐out feature unusually tall common crus. Indeed, crus one greatest height ratios among currently known labyrinths. paratympanic pneumatic system greatly developed similar those extant crocodylians Osteolaemus tetraspis Paleosuchus palpebrosus observations are also discussed context Crocodylomorpha. comparative reinforces previous evaluations complex diverse species, peculiar neuromorphology, particularly eusuchian crocodyliforms.

Language: Английский

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Virtual reconstruction of the neurocranial anatomy of Kansajsuchus extensus (Neosuchia: Paralligatoridae) from the Upper Cretaceous of Tadzhikistan with a review of braincase osteology in Neosuchia

Cretaceous Research, Journal Year: 2024, Volume and Issue: 164, P. 105959 - 105959

Published: Dec. 1, 2024

Language: Английский

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