{"title":"The makers of Rhamphichnus ispp. reinterpreted as lepidosaurian and crocodilian, not pterosaurian","authors":"Anton F.-J. Wroblewski","doi":"10.1016/j.geobios.2022.12.001","DOIUrl":null,"url":null,"abstract":"<div><p><span>Three ichnospecies of the Late Jurassic<span> trace fossil genus </span></span><em>Rhamphichnus</em><span> were first described and interpreted as the walking tracks of non-pterodactyloid pterosaurs like </span><em>Rhamphorhynchus</em>. This despite not resembling any previously identified pterosaur tracks and having a morphology unmatched by pterosaur skeletal elements. To fit the pterosaurian model, elongated imprints of <em>R</em>. <em>pereiraensis</em> and <em>R</em>. <em>lafaurii</em>, displaying four or five digit impressions were interpreted as manus prints, while shorter, five-digit prints were interpreted as imprints made by pedes with dislocated metatarsals and disarticulated phalanges. Comparison of published images and descriptions of <em>Rhamphichnus</em><span> ispp. to skeletal elements of six contemporaneous non-pterodactyloid taxa, skeletons and tracks from pterodactyloid pterosaurs, and modern and ancient lepidosaurs and crocodilians suggests an alternative interpretation. </span><em>R. crayssacensis</em> closely resembles crocodilian (<em>Crocodylopodus</em> (<em>Sustenodactylus</em>) isp.) and crocodylomorph (<em>Batrachopus</em><span> isp.) tracks; its holotype trackway was found 50 cm away from and parallel to a crocodilian swimming trackway with the same sized feet, possibly made by the same individual. </span><em>R</em>. <em>pereiraensis</em> and <em>R</em>. <em>lafaurii</em> strongly resemble lepidosaurian tracks and match the size and morphology of contemporary rhynchocephalians. Prints originally interpreted as manual and pedal in <em>R</em>. <em>pereiraensis</em> and <em>R</em>. <em>lafaurii</em> are reinterpreted and transposed in light of new data from pterosaurian, lepidosaurian, and crocodilian tracks and anatomy. Identification of fossil trackmakers depends on comparisons of a wide range of candidate taxa and elimination of those that cannot be considered further. With this reinterpretation of <em>Rhamphichnus</em>, there are no non-pterodactyloid pterosaurian tracks yet identified in the fossil record.</p></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"77 ","pages":"Pages 71-79"},"PeriodicalIF":1.6000,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geobios","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0016699523000220","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 1
Abstract
Three ichnospecies of the Late Jurassic trace fossil genus Rhamphichnus were first described and interpreted as the walking tracks of non-pterodactyloid pterosaurs like Rhamphorhynchus. This despite not resembling any previously identified pterosaur tracks and having a morphology unmatched by pterosaur skeletal elements. To fit the pterosaurian model, elongated imprints of R. pereiraensis and R. lafaurii, displaying four or five digit impressions were interpreted as manus prints, while shorter, five-digit prints were interpreted as imprints made by pedes with dislocated metatarsals and disarticulated phalanges. Comparison of published images and descriptions of Rhamphichnus ispp. to skeletal elements of six contemporaneous non-pterodactyloid taxa, skeletons and tracks from pterodactyloid pterosaurs, and modern and ancient lepidosaurs and crocodilians suggests an alternative interpretation. R. crayssacensis closely resembles crocodilian (Crocodylopodus (Sustenodactylus) isp.) and crocodylomorph (Batrachopus isp.) tracks; its holotype trackway was found 50 cm away from and parallel to a crocodilian swimming trackway with the same sized feet, possibly made by the same individual. R. pereiraensis and R. lafaurii strongly resemble lepidosaurian tracks and match the size and morphology of contemporary rhynchocephalians. Prints originally interpreted as manual and pedal in R. pereiraensis and R. lafaurii are reinterpreted and transposed in light of new data from pterosaurian, lepidosaurian, and crocodilian tracks and anatomy. Identification of fossil trackmakers depends on comparisons of a wide range of candidate taxa and elimination of those that cannot be considered further. With this reinterpretation of Rhamphichnus, there are no non-pterodactyloid pterosaurian tracks yet identified in the fossil record.
期刊介绍:
Geobios publishes bimonthly in English original peer-reviewed articles of international interest in any area of paleontology, paleobiology, paleoecology, paleobiogeography, (bio)stratigraphy and biogeochemistry. All taxonomic groups are treated, including microfossils, invertebrates, plants, vertebrates and ichnofossils.
Geobios welcomes descriptive papers based on original material (e.g. large Systematic Paleontology works), as well as more analytically and/or methodologically oriented papers, provided they offer strong and significant biochronological/biostratigraphical, paleobiogeographical, paleobiological and/or phylogenetic new insights and perspectices. A high priority level is given to synchronic and/or diachronic studies based on multi- or inter-disciplinary approaches mixing various fields of Earth and Life Sciences. Works based on extant data are also considered, provided they offer significant insights into geological-time studies.