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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Shark mandible evolution reveals patterns of trophic and habitat-mediated diversification

Communications Biology, Journal Year: 2023, Volume and Issue: 6(1)

Published: May 8, 2023

Abstract Environmental controls of species diversity represent a central research focus in evolutionary biology. In the marine realm, sharks are widely distributed, occupying mainly higher trophic levels and varied dietary preferences, mirrored by several morphological traits behaviours. Recent comparative phylogenetic studies revealed that present fairly uneven diversification across habitats, from reefs to deep-water. We show preliminary evidence (disparity) feeding system (mandibles) follows these patterns, we tested hypotheses linking patterns specialisation. conducted 3D geometric morphometric analysis methods on 145 specimens representing 90 extant shark using computed tomography models. explored how rates evolution jaw correlate with habitat, size, diet, level, taxonomic order. Our findings relationship between disparity environment, reef deep-water habitats. Deep-water display highly divergent morphologies compared other sharks. Strikingly, associated deep water, but not reefs. The environmental heterogeneity offshore water column exposes importance this parameter as driver at least early part clade history.

Language: Английский

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Analysing Thalattosuchia palaeobiodiversity through the prism of phylogenetic comparative methods

Palaeontology, Journal Year: 2025, Volume and Issue: 68(1)

Published: Jan. 1, 2025

Abstract Thalattosuchia are a particularly diverse group of mostly marine crocodylomorphs that lived during most the Jurassic and Lower Cretaceous. Previous studies have sought to uncover factors influencing Crocodylomorpha evolution, yielding mixed results, possibly due Thalattosuchia's unique ecological niche controversial phylogenetic placement among crocodylomorphs. Here, we propose Thalattosuchia‐focused study using phylogenetically‐informed statistical analyses. First, tested structure thalattosuchian extinction at various geological transitions. We then influence biotic abiotic explaining diversity aforementioned crises. Finally, whether diet was an additional explanatory factor. found that: (1) Lower–Middle transition phylogenetically structured associated with signs snout reduction explained by colonization emptied niches, allowing emergence Machimosaurinae Geosaurinae; (2) observed higher local temperatures for after Middle–Upper Jurassic–Cretaceous transitions, former being in accordance climatic literature latter subject more caution; finally, (3) corroborated previous about skull shape durophagous teleosauroids tended larger body sizes than any other diet, as result specialization. also evidence partitioning piscivorous macrophagous metriorhynchoids is observable size range extension.

Language: Английский

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A re-description of the teleosauroid Macrospondylus bollensis (Jaeger, 1828) from the Posidonienschiefer Formation of Germany

PalZ, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

Language: Английский

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The ecological diversification and evolution of Teleosauroidea (Crocodylomorpha, Thalattosuchia), with insights into their mandibular biomechanics

Ecology and Evolution, Journal Year: 2022, Volume and Issue: 12(11)

Published: Nov. 1, 2022

Abstract Throughout the Jurassic, a plethora of marine reptiles dominated ocean waters, including ichthyosaurs, plesiosaurs and thalattosuchian crocodylomorphs. These Jurassic ecosystems were characterized by high niche partitioning spatial variation in dietary ecology. However, while ecological diversity many reptile lineages is well known, overall diversification Teleosauroidea (one two major groups within crocodylomorphs) has never been explored. Teleosauroids previously deemed to have morphologically conservative body plan; however, they actuality morphofunctionally more diverse than thought. Here we investigate ecology feeding specializations teleosauroids, using morphological functional cranio‐dental characteristics. We assembled most comprehensive dataset date teleosauroid taxa (approximately 20 species) ran series principal component analyses (PC) categorize them into various ecomorphotypes based on 17 dental characteristics (38 specimens) 16 functionally significant mandibular characters (18 specimens). The results examined conjunction with phylogeny (153 502 characters) evaluate macroevolutionary patterns shifts. Machimosaurids display well‐developed shift from: (1) slender, pointed tooth apices an elongate gracile mandible; (2) robust, teeth slightly deeper finally, (3) rounded deep‐set, shortened mandible enlarged musculature. Overall, there limited variability teleosaurids machimosaurids, despite differing cranial morphologies habitat preferences certain taxa. This suggests narrow divide between machimosaurids. Resource was primarily related snout skull length as habitat; only twice did teleosauroids manage make evolutionary leap feed distinctly differently, derived machimosaurines successfully radiating new ecologies.

Language: Английский

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Prey size and ecological separation in spinosaurid theropods based on heterodonty and rostrum shape

The Anatomical Record, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 28, 2024

Members of the dinosaur clade Spinosauridae had numerous traits attributed to feeding in or around water, and their apparatus has often been considered analogous modern crocodylians. Here we quantify craniodental morphology compare it Crocodylia. We measured from spinosaurid crocodylian skeletal material area alveoli as a proxy for tooth size determine size-heterodonty. Geometric morphometrics were also conducted on crowns bearing regions skull. Spinosaurids overall relatively large alveoli, both they, crocodylians, isolated enlarged alveoli. Spinosaurines along caudal dentary that baryonychines lacked, which instead additional positions. Size-heterodonty was positively allometric, spinosaurids overlapped with generalist/macro-generalist crocodylians similar sizes. Spinosaurid crown shape morphologies certain slender-longirostrine yet lacked molariform distal typical most rostra mandibles deep undulating margins correlating local sizes, may indicate developmental constraint. particularly long concavity rosette anterior cranial teeth, corresponding bulbous rostral dentary. The well suited quickly striking creating punctures, but not cutting flesh durophagy. jaws interlocked secure prey move deeper into mouth. probably did little oral processing, spinosaurines could have processed vertebrates. Overall, there is no indication restricted fish small aquatic prey.

Language: Английский

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Oldest record of Machimosaurini (Thalattosuchia, Teleosauroidea): teeth and scavenging traces from the Middle Jurassic (Bajocian) of Switzerland

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(4)

Published: April 1, 2024

The Jurassic period was a time of major diversification for Mesozoic marine reptiles, including Ichthyosauria, Plesiosauria and thalattosuchian Crocodylomorpha. latter originated in the Early thrived during Late Jurassic. Unfortunately, Middle Jurassic, crucial their evolution, has poor fossil record. Here, we document first evidence macrophagous/durophagous Machimosaurini-tribe teleosauroid thalattosuchians from late Bajocian ( ca 169 Ma) form three robust tooth crowns with conical blunt shapes anastomosed pattern thick enamel ridges towards apex, associated skeleton large ichthyosaur lacking preserved crowns. were found on posterior section lower jaw (left angular), lacrimal axis neural arch ichthyosaur. In addition, some distal sections dorsal ribs exhibit rounded bite marks elongated furrows that fit size shape Machimosaurini teeth. These marks, together absence healing rib bone are interpreted here as indicators peri- to post-mortem scavenging by after carcass settled floor shallow ocean.

Language: Английский

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Palaeohistology of Macrospondylus bollensis (Crocodylomorpha: Thalattosuchia: Teleosauroidea) from the Posidonienschiefer Formation (Toarcian) of Germany, with insights into life history and ecology

The Anatomical Record, Journal Year: 2024, Volume and Issue: 308(2), P. 342 - 368

Published: Sept. 28, 2024

Abstract The Posidonienschiefer Formation of southern Germany has yielded an array incredible fossil vertebrates. One the best represented clades therein is Teleosauroidea, a successful thalattosuchian crocodylomorph group that dominated coastlines. most abundant teleosauroid, Macrospondylus bollensis , known from wide range body sizes, making it ideal taxon for histological and ontogenetic investigations. Previous studies examining histology provide basic understanding bone microstructure in teleosauroids, but lack taxonomic, stratigraphic, control required to understand growth palaeobiology within species. Here, we examine three femora one tibia different‐sized M. individuals. We also perform compactness analyses evaluate ecological variation. Our results suggests (1) smallest specimen was young, skeletally immature individual with well‐vascularized‐parallel‐fibered limited remodeling midshaft periosteal cortex; (2) intermediate at death, vascularized parallel‐fibered tissue interrupted by least 10 LAGs, no clear external fundamental system (EFS), rather extensive inner cortical remodeling; (3) largest mature, numerous well‐developed EFS, deep cortex. grew relatively regularly until reaching adult size, global values fall reported modern crocodylians. lifestyle inference models used suggest well adapted aquatic environment retained some ability move on land. Finally, both larger specimens display peculiar, localized area disorganized interpreted as pathological.

Language: Английский

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Evaluating growth in Macrospondylus bollensis (Crocodylomorpha, Teleosauroidea) in the Toarcian Posidonia Shale, Germany

Papers in Palaeontology, Journal Year: 2023, Volume and Issue: 9(5)

Published: Sept. 1, 2023

Abstract The study of how organisms grow is a fundamental aspect palaeontology. Growth in teleosauroids poorly understood and little studied, especially an ontogenetic sense. We investigate growth rates the most common abundant teleosauroid, Macrospondylus bollensis , which large sample multiple body sizes available from Posidonienschiefer Formation (Posidonia Shale) southwestern Germany. perform linear regression analyses on 62 specimens (16 juveniles, 7 subadults 39 adults) using 21 cranial postcranial measurements. Our results show that juvenile, subadult adult individuals have near‐isometric or isometric throughout much body. Notably, we find : (1) femur grows at faster rate than skull hindlimb zeugopodium; (2) forelimb same rate; (3) there distinct signal orbit supratemporal fenestra. also limb scaling somewhat comparable to seen extant gavialids Gavialis gangeticus Tomistoma schlegelii . Last, examine evolutionary allometry length relative size Crocodylomorpha femoral as proxy, shows trend. Non‐thalattosuchian crocodylomorphs (with exception one pholidosaurid dryosaurid taxon) are differentiated thalattosuchians due their shorter skulls, previously suggested, but relationship with remains unchanged.

Language: Английский

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Limited convergence in the postcranium of aquatic Crocodylomorpha

Palaeontology, Journal Year: 2023, Volume and Issue: 66(6)

Published: Nov. 1, 2023

Abstract Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous Eocene) are crocodylomorph archosaurs which diversified in fluvial marine environments endured extinction events (i.e. Jurassic–Cretaceous boundary for Thalattosuchia; Cretaceous–Palaeogene Dyrosauridea). Their postcrania remain globally undervalued anatomical descriptions diagnoses, shrouding the locomotive adaptations that possibly underpinned their radiations longevity. We thoroughly surveyed postcranial morphology of Thalattosuchia, recreated girdles three‐dimensions using tens high‐precisions 3D scans, analysed shape geometric morphometrics. have clearly distinct postcrania, even when found within similar environments, suggesting existence clade‐specific features limiting strength evolutionary convergence. Moreover, range morphologies evolved by dyrosaurids thalattosuchians is large compared extant crocodylians, making latter unsatisfactory functional analogues every group extinct crocodylomorphs. Our work reveals previously unsuspected potential anatomy as an abundant source phylogenetic taxonomic characters assess relationships Crocodylomorpha. Incorporation therefore appears crucial fully ecology, disparity,

Language: Английский

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