First record of Carcharodontosauridae (Dinosauria, Theropoda) in the Upper Cretaceous Khodzhakul Formation of Uzbekistan

Journal of Paleontology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 13

Published: April 21, 2025

Abstract The allosauroid theropod dinosaurs of the clade Carcharodontosauridae were apex predators in terrestrial ecosystems Early Cretaceous but replaced this ecological niche by Tyrannnosauridae Late Cretaceous. Details turnover are poorly known because only two transitional ecosystems, containing both carcharodontosaurids and tyrannosauroids, had been recognized to date (Cenomanian Cedar Mountain Formation Utah, USA, Turonian Bissekty Uzbekistan). Moreover, presence Formation, based on a maxilla fragment identified as Ulughbegsaurus uzbekistanensis Tanaka et al., 2021, has recently questioned. Here we report third ecosystem clades predators, Cenomanian Khodzhakul Uzbekistan. This new occurrence is newly that closely resembles holotype U. sp. revised morphological characters specimens support attribution Carcharodontosauridae. We novel neurovascular feature maxilla—a medial alveolar canal supplied alveoli medially contained tributaries palatine vessels Ulughbegsaurus.

Language: Английский

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Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology

Science, Journal Year: 2023, Volume and Issue: 379(6639), P. 1348 - 1352

Published: March 31, 2023

Large theropod dinosaurs are often reconstructed with their marginal dentition exposed because of the enormous size teeth and phylogenetic association to crocodylians. We tested this hypothesis using a multiproxy approach. Regressions skull length tooth for range theropods extant varanid lizards confirm that complete coverage dinosaur extraoral tissues (gingiva labial scales) is both plausible consistent patterns observed in living ziphodont amniotes. Analyses dental histology from crocodylians dinosaurs, including Tyrannosaurus rex, further indicate most likely condition was tissue when mouth closed. This changes our perceptions about appearance oral configuration these iconic predators has broad implications interpretations other terrestrial animals large teeth.

Language: Английский

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At the root of the mammalian mind: The sensory organs, brain and behavior of pre-mammalian synapsids

Progress in brain research, Journal Year: 2022, Volume and Issue: unknown, P. 25 - 72

Published: Nov. 18, 2022

Language: Английский

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Pachyosteosclerosis, rhamphotheca and enhanced sensory capabilities of the premaxillae of Hyperodapedon (Archosauromorpha, Rhynchosauria): implications for foraging at the sediment–water interface

Palaeontology, Journal Year: 2022, Volume and Issue: 65(6)

Published: Nov. 1, 2022

Abstract The external morphology and microanatomy of 32 partial complete Hyperodapedon premaxillae was examined to assess their functional attributes. This revealed morphological correlates for innervation in the form posteriorly opening enlarged neurovascular foramina associated with several grooves, a prominent sulcus. Scanning electron microscopy shows numerous small, circular clusters along lateroventral surface towards anterior tip ventral edge, often preferred orientation. These are found high rugosity elongated anterolateral depression, were related nutrient supply and/or part system. Selected show extremely bone compactness indices (especially at end) suggesting specialized osteosclerotic conditions, dense compact microstructure almost no clear transition between outer cortex inner core. With ontogeny, became lateromedially thickened by deposition lamellar zonal bone, highly vascularized from intense Haversian remodelling, pachyosteosclerosis premaxillae. Other characteristic features include profuse open vascular channels or frayed margin anteroventral tip, bundles long wavy extrinsic fibres. features, compactness, decrease naris. It is proposed that covered keratinized epithelium rhamphotheca end, had heightened sensory capabilities aided foraging mussels other invertebrates soft sediments under shallow water. Such enhanced capability reported first time an early‐diverging archosauromorph.

Language: Английский

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Modified skulls but conservative brains? The palaeoneurology and endocranial anatomy of baryonychine dinosaurs (Theropoda: Spinosauridae)

Journal of Anatomy, Journal Year: 2023, Volume and Issue: 242(6), P. 1124 - 1145

Published: Feb. 13, 2023

Abstract The digital reconstruction of neurocranial endocasts has elucidated the gross brain structure and potential ecological attributes many fossil taxa, including Irritator , a spinosaurine spinosaurid from “mid” Cretaceous (Aptian) Brazil. With unexceptional hearing capabilities, this taxon was inferred to integrate rapid controlled pitch‐down movements head that perhaps aided in predation small agile prey such as fish. However, neuroanatomy baryonychine spinosaurids remains be described, potentially informs on condition early spinosaurids. Using micro‐computed tomographic scanning (μCT), we reconstruct braincase Baryonyx walkeri Ceratosuchops inferodios Wealden Supergroup (Lower Cretaceous) England. We show endocranial morphology is similar other non‐maniraptoriform theropods, corroborates previous observations overall conservatism amongst more basal theropods. Several differences unknown taxonomic utility are noted between pair. Baryonychine neurosensory capabilities include low‐frequency olfaction, whilst differing floccular lobe tentatively suggests less developed gaze stabilisation mechanisms relative spinosaurines. Given morphological similarities observed with tetanurans, baryonychines likely possessed comparable behavioural sophistication, suggesting transition terrestrial hypercarnivorous ancestors semi‐aquatic “generalists” during evolution Spinosauridae did not require substantial modification sensory systems.

Language: Английский

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Early synapsids neurosensory diversity revealed by CT and synchrotron scanning

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

Published: April 10, 2024

Abstract Non‐mammaliaform synapsids (NMS) represent the closest relatives of today's mammals among early amniotes. Exploring their brain and nervous system is key to understanding how evolved. Here, using CT Synchrotron scanning, we document for first time three extreme cases neurosensory behavioral adaptations that probe into wide range unexpected NMS paleoneurological diversity. First, describe low‐frequency hearing low‐light conditions in non‐mammalian cynodont Cistecynodon parvus , supporting an obligatory fossorial lifestyle. Second, uniquely complex three‐dimensional maxillary canal morphology biarmosuchian Pachydectes elsi which suggests it may have used its cranial bosses display or low‐energy combat. Finally, introduce a paleopathology found skull Moschognathus whaitsi . Since specimen was not fully grown, this condition possibility species might engaged playful fighting as juveniles—a behavior both social structured. Additionally, paper discusses other evidence could indicate tapinocephalid dinocephalians were animals, living interacting closely with one another. Altogether, these examples diversity neurological structures NMS.

Language: Английский

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Predicting behavior in extinct reptiles from quantitative analysis of trigeminal osteological correlates

Frontiers in Amphibian and Reptile Science, Journal Year: 2024, Volume and Issue: 2

Published: July 2, 2024

Introduction Vertebrate sensory systems are in close contact with surrounding tissues, often leaving bony signatures behind. These features the keys to assessing variation fossil taxa. The trigeminal system (e.g., ganglion, ophthalmic, maxillary, and mandibular divisions) has osteological correlates throughout skull, including braincase fossa, prootic notch, ophthalmic maxillomandibular foramina) rostrum canal, neurovascular foramina). Methods Here we measured compared these among a morphologically, phylogenetically, ecologically diverse sample of sauropsids determine strength explore ecomorphological trends. We determined several suitable for soft tissue discounted foramen count alone as correlate. However, when size was accounted for, becomes useful indicator ecology. Results discussion Among extant taxa, those engaging tactile behaviors face exhibit relatively larger tissues than not behaviors. Though patterns unclear clades, both relative feature sizes models used predict capacity reveal trend increasing sensitivity along pseudosuchian lineage. Overall, quantitative assessment trends proves informative hypotheses behavior extinct taxa supports use similar methods other correlates.

Language: Английский

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Cranial anatomy of the Triassic rhynchosaur Mesosuchus browni based on computed tomography, with a discussion of the vomeronasal system and its deep history in Reptilia

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 201(4)

Published: Aug. 1, 2024

Abstract The stem lineage of Archosauria is populated by a diverse fossil record that remains notably understudied relative to the crown clade. Prominent among these specimens beautifully preserved skull early mid-Triassic rhynchosaur Mesosuchus browni [Iziko South African Museum (SAM) 6536], whose phylogenetic position has considerable influence on patterns pan-archosaurian cranial evolution. We used high-resolution, micro-computed tomography re-examine anatomy this specimen, building previous studies were either limited external observations or restricted braincase. A digital segmentation elements and primary neurovascular canals SAM-PK-6536 allows for expanded character scoring constitutes foundation future comparative insights. Our data support phylogenetically oldest instance pneumatized maxilla in pan-archosaur, bringing antorbital pneumatization into closer alignment with neurocranium. nasal cavity palate includes complex septomaxilla, novel element anterior vomer, likely have supported well-developed vomeronasal system. evolution system discussed terms both pattern how skeletal architecture other fossils could inform signalling dynamics during development.

Language: Английский

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Synapsids and sensitivity: Broad survey of tetrapod trigeminal canal morphology supports an evolutionary trend of increasing facial tactile specialization in the mammal lineage

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

Published: Nov. 24, 2024

Abstract The trigeminus nerve (cranial V) is a large and significant conduit of sensory information from the face to brain, with its three branches extending over head innervate wide variety integumentary receptors, primarily tactile. paths maxillary (V 2 ) mandibular 3 divisions frequently transit through dedicated canals within bones upper lower jaws, thus allowing this neuroanatomy be captured in fossil record available interpretations ability extinct taxa. Here, we use microCT synchrotron scans 38 extant species spanning phylogenetic sample across tetrapods investigate whether canal morphology can informative biology synapsid lineage. We found that comparison an amphibian sauropsid outgroup, synapsids demonstrate distinctive evolutionary pattern change are highly ramified near rostral tip jaws increasingly simplified morphology. This especially evident canal, which came feature shortened infraorbital terminating single foramen serves as outlet for V then enter soft tissues face. A modern analogues supports hypothesis morphological correlates history synapsid‐specific innovations facial touch. interpret transitional form early nonmammalian indicative enhanced tactile sensitivity rostrum via direct or proximal contact, similar specialists such probing shorebirds alligators possess proliferative ramifications canals. transition toward derived emerged among Mid‐Triassic prozostrodont cynodonts retained mammals unique configuration correlated equally novel apparatus: mobile mystacial whiskers. Our survey ecological highlights diversity these structures, but also need establish robust form‐function relationships future osteological biology.

Language: Английский

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HISTOLOGIA DENTAL DE ARCOSSAUROS DO TRIÁSSICO SUPERIOR DO RIO GRANDE DO SUL (RESULTADOS PARCIAIS)

Published: Dec. 11, 2024

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