New data on the postcranial skeleton of the tapejarid Sinopterus from the Early Cretaceous Jehol Biota

ABSTRACT We reported a new skeleton of the tapejarid Sinopterus from the Jehol Biota, providing more additional information of the postcranial morphology, especially the anatomy of the tail, the pectoral and the pelvic girdles. The reduced tail is composed of nine caudal vertebrae, as a new evidence of the tail reduction of the azhdarchoids. An eminence is present on the posterior surface above the coracoidal crest, as the first record in the Jehol tapejarids, comparable with the modest coracoidal tubercle of the Brazilian tapejarids Caiuajara, Keresdrakon, and Tupandactylus, which implies a coexistence of the coracoidal crest and the coracoidal tubercle in the tapejarids. The pelvic girdle has an elongate pre-acetabular process, a hatchet-like postacetabular process, a medium-sized obturator foramen, and a kidney-shaped prepubic blade. The postacetabular process is unconstricted in the mid-shaft, and its terminus is subequal to the acetabulum in length, distinct from the more derived condition in the Brazilian tapejarids. This discovery sheds a new light on the evolution of the postcranial morphology in tapejarids and azhdarchoids.

[1]  B. Andres,et al.  Morphology and Taxonomy of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea) , 2021, Journal of Vertebrate Paleontology.

[2]  B. Andres.  Phylogenetic Systematics of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea) , 2021, Journal of Vertebrate Paleontology.

[3]  M. Kundrát,et al.  A new specimen of Sinopterus dongi (Pterosauria, Tapejaridae) from the Jiufotang Formation (Early Cretaceous, China) , 2021, PeerJ.

[4]  F. Pinheiro,et al.  Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade , 2021, PloS one.

[5]  D. Naish,et al.  Powered flight in hatchling pterosaurs: evidence from wing form and bone strength , 2021, Scientific Reports.

[6]  Xiaolin Wang,et al.  Short note on the vertebral column of the Tapejaridae (Pterosauria, Pterodactyloidea) based on a new specimen from the Crato Formation (late Aptian, Early Cretaceous), northeast Brazil , 2020 .

[7]  D. Martill,et al.  A new tapejarid (Pterosauria, Azhdarchoidea) from the mid-Cretaceous Kem Kem beds of Takmout, southern Morocco , 2020, Cretaceous Research.

[8]  B. Holgado,et al.  A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert. , 2019, Anais da Academia Brasileira de Ciencias.

[9]  Xiaolin Wang,et al.  New Material of Sinopterus (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota of China. , 2019, Anais da Academia Brasileira de Ciencias.

[10]  A. Kellner,et al.  New information on the postcranial skeleton of the Thalassodrominae (Pterosauria, Pterodactyloidea, Tapejaridae) , 2018 .

[11]  Chang-Fu Zhou,et al.  The toothless pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications , 2017, PloS one.

[12]  Junchang Wang,et al.  New data on the cervical morphology of the Chinese tapejarine , 2015 .

[13]  Alexander W A Kellner.  Comments on Triassic pterosaurs with discussion about ontogeny and description of new taxa. , 2015, Anais da Academia Brasileira de Ciencias.

[14]  C. Fragoso,et al.  Discovery of a Rare Pterosaur Bone Bed in a Cretaceous Desert with Insights on Ontogeny and Behavior of Flying Reptiles , 2014, PloS one.

[15]  A. Kellner,et al.  New postcranial elements of the Thalassodrominae (Pterodactyloidea, Tapejaridae) from the Romualdo Formation (Aptian–Albian), Santana Group, Araripe Basin, Brazil , 2014 .

[16]  J. Lü,et al.  New Material of Zhenyuanopterus (Pterosauria) from the Early Cretaceous Yixian Formation of Western Liaoning , 2014 .

[17]  G. Dyke,et al.  A New Small-Bodied Azhdarchoid Pterosaur from the Lower Cretaceous of England and Its Implications for Pterosaur Anatomy, Diversity and Phylogeny , 2013, PloS one.

[18]  D. Hone,et al.  A New Chinese Anurognathid Pterosaur and the Evolution of Pterosaurian Tail Lengths , 2012 .

[19]  C. Meyer,et al.  The oldest azhdarchoid pterosaur from the Late Jurassic Solnhofen Limestone (Early Tithonian) of Southern Germany , 2011 .

[20]  E. Frey,et al.  On the osteology of Tapejara wellnhoferi KELLNER 1989 and the first occurrence of a multiple specimen assemblage from the Santana Formation, Araripe Basin, NE-Brazil , 2011 .

[21]  Zhonghe Zhou,et al.  Discovery of a rare arboreal forest-dwelling flying reptile (Pterosauria, Pterodactyloidea) from China , 2008, Proceedings of the National Academy of Sciences.

[22]  Laura Codorniú.  Morfología caudal de Pterodaustro guinazui (Pterosauria: Ctenochasmatidae) del Cretácico de Argentina , 2005 .

[23]  Zhonghe Zhou,et al.  A new pterosaur (Pterodactyloidea, Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning, China and its implications for biostratigraphy , 2003 .

[24]  S. Bennett.  The Osteology and Functional Morphology of the Late Cretaceous Pterosaur Pteranodon Part I. General Description of Osteology , 2001, Palaeontographica Abteilung A.

[25]  S. Bennett.  A pterodactyloid pterosaur pelvis from the Santana Formation of Brazil: implications for terrestrial locomotion , 1990 .

[26]  D. Martill,et al.  Evolution of the Pterosaur Pelvis , 2012 .

[27]  L. Chiappe,et al.  Early juvenile pterosaurs (Pterodactyloidea: Pterodaustro guinazui) from the Lower Cretaceous of central Argentina , 2004 .

[28]  M Analoui,et al.  Direct digital radiography for caries detection and analysis. , 2000, Monographs in oral science.

[29]  Y. Tomida,et al.  Description of a new species of Anhangueridae(Pterodactyloidea) with comments on the pterosaur fauna from the Santana Formation(Aptian-Albian), northeastern Brazil , 2000 .

[30]  S. Bennett.  The ontogeny of Pteranodon and other pterosaurs , 1993, Paleobiology.

[31]  Peter Wellnhofer,et al.  The illustrated encyclopedia of pterosaurs , 1991 .