Abstract
We report a new, small-sized atoposaurid crocodyliform from the Upper Jurassic of Langenberg, Northeastern Germany. Atoposaurids are small-sized Mesozoic crocodyliforms of mainly European distribution, which are considered to be phylogenetically close to the origin of Eusuchia. Knoetschkesuchus langenbergensis gen. nov. sp. nov. is represented by two well-preserved skulls and additional cranial and postcranial remains representing different ontogenetic stages. 3D reconstructions of a juvenile skull based on micro-computed tomography allow the most detailed description of cranial remains of any atoposaurid hitherto presented. Our new analysis contradicts previous preliminary assignment of the Langenberg atoposaurids to Theriosuchus. Knoetschkesuchus gen. nov. is characterized in particular by the presence of two dental morphotypes in the maxilla and dentary, slit-like secondary choanae within a narrow groove on the surface of the pterygoid, absence of lacrimonasal contact, presence of an antorbital foramen and an external mandibular fenestra, and proportional characters of the interorbital and intertemporal region. A similar combination of characters allows attribution of Theriosuchus guimarotae to Knoetschkesuchus, forming the new combination Knoetschkesuchus guimarotae. Our analysis provides an osteological basis for the separation of Theriosuchus and Knoetschkesuchus and helps further delineate generic differences in other closely related crocodylomorphs. Our phylogenetic analysis corroborates inclusion of Knoetschkesuchus into Atoposauridae and supports a position of Atoposauridae within Eusuchia.
Highlights
The discovery of the dwarfed sauropod dinosaur Europasaurus holgeri made the Langenberg Quarry a fossil locality of world-wide importance [1]
Atoposauridae is a family of small sized crocodyliforms typically smaller than one meter in body length that was first described by the French palaeontologist Gervais in 1871 [9]
In addition to the teeth and skeletons of small non-marine atoposaurid crocodylians described [6,7,8], the Langenberg Quarry is well known as the type and only locality of the dwarfed sauropod Europasaurus holgeri [34,35,36]
Summary
The discovery of the dwarfed sauropod dinosaur Europasaurus holgeri made the Langenberg Quarry a fossil locality of world-wide importance [1]. The marly limestones at the Langenberg near Goslar, deposited in a shallow marine inlet or a small marginal basin of the German Late Jurassic Basin [2, 3], yield a high diversity of invertebrate, micro- and macrovertebrate as well as plant fossils [4, 5] Among these fossils are the remains of marine and terrestrial atoposaurid crocodylians [6,7,8], which here are described for the first time in detail for the first time. In addition to the teeth and skeletons of small non-marine atoposaurid crocodylians described [6,7,8], the Langenberg Quarry is well known as the type and only locality of the dwarfed sauropod Europasaurus holgeri [34,35,36]. The onset of disarticulation of the carcasses is evident in DFMMh/FV 200 (Fig 3) and to a smaller degree in DFMMh/FV 605, suggesting weak currents and an exposure time of several days before burial
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
