Stephan N. F. Spiekman, Richard J. Butler, Susannah C. R. Maidment
{"title":"威尔士晚三叠世 Terrestrisuchus gracilis(古龙类,鳄形目)的颅后解剖学和骨组织学","authors":"Stephan N. F. Spiekman, Richard J. Butler, Susannah C. R. Maidment","doi":"10.1002/spp2.1577","DOIUrl":null,"url":null,"abstract":"The earliest crocodylomorphs, known as non‐crocodyliform crocodylomorphs, first appeared during the Late Triassic. In contrast to extant crocodylians, which are all semi‐aquatic, early crocodylomorphs represent terrestrial taxa with a fully erect posture and in most cases a small body size. Their gracile skeletons suggest an active mode of life, possibly similar to contemporaneous, bipedal theropod dinosaurs. Despite this remarkable body plan, the postcranial morphology of early crocodylomorphs has rarely been documented in detail, restricting our ability to infer aspects of their functional morphology and evolution. Here, we provide a detailed description of the postcranium of <jats:italic>Terrestrisuchus gracilis</jats:italic>, a small‐bodied crocodylomorph from the Late Triassic of Pant‐y‐Ffynnon Quarry (southern Wales, UK), including a description of long bone tissues based on histological thin sections. Almost all elements of the postcranial skeleton have been preserved. The skeleton of <jats:italic>Terrestrisuchus gracilis</jats:italic> is highly gracile, even for a non‐crocodyliform crocodylomorph. Osteological correlates of the appendicular skeleton suggest that <jats:italic>Terrestrisuchus gracilis</jats:italic> had a digitigrade, quadrupedal posture. A quantitative analysis of limb robustness corroborates that <jats:italic>Terrestrisuchus gracilis</jats:italic> was a quadruped. Histological analysis suggests that all sampled specimens were skeletally immature and had fast growth at the time of death, as indicated by the lack of an external fundamental system and the predominance of fibrolamellar bone. The bone tissue is similar to that recently described for <jats:italic>Saltoposuchus connectens</jats:italic> and certain non‐crocodylomorph pseudosuchians, but differs from <jats:italic>Hesperosuchus agilis</jats:italic> and crocodyliforms, in which parallel‐fibred bone is more prevalent.","PeriodicalId":48705,"journal":{"name":"Papers in Palaeontology","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The postcranial anatomy and osteohistology of Terrestrisuchus gracilis (Archosauria, Crocodylomorpha) from the Late Triassic of Wales\",\"authors\":\"Stephan N. F. Spiekman, Richard J. Butler, Susannah C. R. Maidment\",\"doi\":\"10.1002/spp2.1577\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The earliest crocodylomorphs, known as non‐crocodyliform crocodylomorphs, first appeared during the Late Triassic. In contrast to extant crocodylians, which are all semi‐aquatic, early crocodylomorphs represent terrestrial taxa with a fully erect posture and in most cases a small body size. Their gracile skeletons suggest an active mode of life, possibly similar to contemporaneous, bipedal theropod dinosaurs. Despite this remarkable body plan, the postcranial morphology of early crocodylomorphs has rarely been documented in detail, restricting our ability to infer aspects of their functional morphology and evolution. Here, we provide a detailed description of the postcranium of <jats:italic>Terrestrisuchus gracilis</jats:italic>, a small‐bodied crocodylomorph from the Late Triassic of Pant‐y‐Ffynnon Quarry (southern Wales, UK), including a description of long bone tissues based on histological thin sections. Almost all elements of the postcranial skeleton have been preserved. The skeleton of <jats:italic>Terrestrisuchus gracilis</jats:italic> is highly gracile, even for a non‐crocodyliform crocodylomorph. Osteological correlates of the appendicular skeleton suggest that <jats:italic>Terrestrisuchus gracilis</jats:italic> had a digitigrade, quadrupedal posture. A quantitative analysis of limb robustness corroborates that <jats:italic>Terrestrisuchus gracilis</jats:italic> was a quadruped. Histological analysis suggests that all sampled specimens were skeletally immature and had fast growth at the time of death, as indicated by the lack of an external fundamental system and the predominance of fibrolamellar bone. The bone tissue is similar to that recently described for <jats:italic>Saltoposuchus connectens</jats:italic> and certain non‐crocodylomorph pseudosuchians, but differs from <jats:italic>Hesperosuchus agilis</jats:italic> and crocodyliforms, in which parallel‐fibred bone is more prevalent.\",\"PeriodicalId\":48705,\"journal\":{\"name\":\"Papers in Palaeontology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2024-07-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Papers in Palaeontology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1002/spp2.1577\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PALEONTOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Papers in Palaeontology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/spp2.1577","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
The postcranial anatomy and osteohistology of Terrestrisuchus gracilis (Archosauria, Crocodylomorpha) from the Late Triassic of Wales
The earliest crocodylomorphs, known as non‐crocodyliform crocodylomorphs, first appeared during the Late Triassic. In contrast to extant crocodylians, which are all semi‐aquatic, early crocodylomorphs represent terrestrial taxa with a fully erect posture and in most cases a small body size. Their gracile skeletons suggest an active mode of life, possibly similar to contemporaneous, bipedal theropod dinosaurs. Despite this remarkable body plan, the postcranial morphology of early crocodylomorphs has rarely been documented in detail, restricting our ability to infer aspects of their functional morphology and evolution. Here, we provide a detailed description of the postcranium of Terrestrisuchus gracilis, a small‐bodied crocodylomorph from the Late Triassic of Pant‐y‐Ffynnon Quarry (southern Wales, UK), including a description of long bone tissues based on histological thin sections. Almost all elements of the postcranial skeleton have been preserved. The skeleton of Terrestrisuchus gracilis is highly gracile, even for a non‐crocodyliform crocodylomorph. Osteological correlates of the appendicular skeleton suggest that Terrestrisuchus gracilis had a digitigrade, quadrupedal posture. A quantitative analysis of limb robustness corroborates that Terrestrisuchus gracilis was a quadruped. Histological analysis suggests that all sampled specimens were skeletally immature and had fast growth at the time of death, as indicated by the lack of an external fundamental system and the predominance of fibrolamellar bone. The bone tissue is similar to that recently described for Saltoposuchus connectens and certain non‐crocodylomorph pseudosuchians, but differs from Hesperosuchus agilis and crocodyliforms, in which parallel‐fibred bone is more prevalent.
期刊介绍:
Papers in Palaeontology is the successor to Special Papers in Palaeontology and a journal of the Palaeontological Association (www.palass.org). The journal is devoted to the publication of papers that document the diversity of past life and its distribution in time and space.
Papers in Palaeontology is devoted to the publication of papers that document the diversity of past life and its distribution in time and space. As a sister publication to Palaeontology its focus is on descriptive research, including the descriptions of new taxa, systematic revisions of higher taxa, detailed biostratigraphical and biogeographical documentation, and descriptions of floras and faunas from specific localities or regions. Most contributions are expected to be less than 30 pp long but longer contributions will be considered if the material merits it, including single topic parts.
The journal publishes a wide variety of papers on palaeontological topics covering:
palaeozoology,
palaeobotany,
systematic studies,
palaeoecology,
micropalaeontology,
palaeobiogeography,
functional morphology,
stratigraphy,
taxonomy,
taphonomy,
palaeoenvironmental reconstruction,
palaeoclimate analysis,
biomineralization studies.