Bioinspiration is an approach to innovation based on the observation of biological systems, of which only 0.1% remain since life began 3.7 billion years ago.
View Article and Find Full Text PDFThe fossil fish Agassiz, 1834, characterized by a highly distinctive grinding dentition and an estimated gigantic body size (up to around 10 m), has remained one of the most enigmatic extinct elasmobranchs (i.e. sharks, skates and rays) for nearly two centuries.
View Article and Find Full Text PDFIn the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, , of early Maastrichtian age in Magallanes, Chile.
View Article and Find Full Text PDFThe ecomorphological diversity of extinct elasmobranchs is incompletely known. Here, we describe , a bizarre probable planktivorous shark from early Late Cretaceous open marine deposits in Mexico. , tentatively assigned to Lamniformes, is characterized by hypertrophied, slender pectoral fins.
View Article and Find Full Text PDFPreceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining the terminus ante quem for the pelvis to 11311±370 y BP.
View Article and Find Full Text PDFThe mobility of ray I was analysed in seventy-eight Early Permian to Late Cretaceous specimens of non-mammalian Synapsida and one extant mammal. In all non-mammaliamorph Synapsida investigated, ray I formed a digital arcade. The first phalanx was maximally extendable to the zero position in the metapodiophalangeal joint I.
View Article and Find Full Text PDFAnat Rec (Hoboken)
December 2014
Pterosaurs were the first vertebrates to achieve active flight, with some derived forms reaching enormous size. Accumulating fossil evidence confirms earlier indications that selection for large size in these flying forms resulted in a light, yet strong skeleton characterized by fusion of many bones of the trunk. However, this process also added mechanical constraints on the mobility of the thorax of large pterosaurs that likely limited the options available for lung ventilation.
View Article and Find Full Text PDFBackground: The 'Solnhofen Limestone' beds of the Southern Franconian Alb, Bavaria, southern Germany, have for centuries yielded important pterosaur specimens, most notably of the genera Pterodactylus and Rhamphorhynchus. Here we describe a new genus of non-pterodactyloid pterosaur based on an extremely well preserved fossil of a young juvenile: Bellubrunnus rothgaengeri (gen. et sp.
View Article and Find Full Text PDFAssociations of large vertebrates are exceedingly rare in the Late Jurassic Solnhofen Limestone of Bavaria, Southern Germany. However, there are five specimens of medium-sized pterosaur Rhamphorhynchus that lie adjacent to the rostrum of a large individual of the ganoid fish Aspidorhynchus. In one of these, a small leptolepidid fish is still sticking in the esophagus of the pterosaur and its stomach is full of fish debris.
View Article and Find Full Text PDFOn the basis of a new, three-dimensionally preserved specimen of the Early Jurassic pterosaur Dorygnathus banthensis we present a reinterpretation of the pterosaur palate. The hard palate is formed by the extensive palatal plate of the maxilla and not by the palatine as has been generally reconstructed. This palatal plate of the maxilla emarginates the choana rostrally and rostrolaterally as in other archosaurs and lepidosaurs.
View Article and Find Full Text PDFThe pre-sacral vertebrae of most sauropod dinosaurs were surrounded by interconnected, air-filled diverticula, penetrating into the bones and creating an intricate internal cavity system within the vertebrae. Computational finite-element models of two sauropod cervical vertebrae now demonstrate the mechanical reason for vertebral pneumaticity. The analyses show that the structure of the cervical vertebrae leads to an even distribution of all occurring stress fields along the vertebrae, concentrated mainly on their external surface and the vertebral laminae.
View Article and Find Full Text PDFAnat Rec (Hoboken)
January 2007
The orientation of the scapulocoracoid in sauropod dinosaurs is reconstructed based on comparative anatomical investigations of pectoral girdles of extant amniotes. In the reconstruction proposed here, the scapula of sauropods stands at an angle of at least 55 degrees to the horizontal plane in mechanical coherence with the sternal apparatus including the coracoids. The coracoids are oriented cranioventrally to the rib cage and the glenoid is directed mediolaterally, which allows the humerus to swing in a sagittal plane.
View Article and Find Full Text PDFProc Biol Sci
October 2006
While the crocodyliform lineage extends back over 200 million years (Myr) to the Late Triassic, modern forms-members of Eusuchia-do not appear until the Cretaceous. Eusuchia includes the crown group Crocodylia, which comprises Crocodyloidea, Alligatoroidea and Gavialoidea. Fossils of non-crocodylian eusuchians are currently rare and, in most instances, fragmentary.
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