Papers by Christophe Hendrickx
Theropod teeth are typically not described in detail, yet these abundant vertebrate fossils are n... more Theropod teeth are typically not described in detail, yet these abundant vertebrate fossils are not only frequently reported in the literature, but also preserve extensive anatomical information. Often in descriptions, important characters of the crown and ornamentations are omitted, and in many instances, authors do not include a description of theropod dentition at all. The paucity of information makes identification of isolated teeth difficult and taxonomic assignments uncertain. Therefore, we here propose a standardization of the anatomical and morphometric terms for tooth anatomical subunits, as well as a methodology to describe isolated teeth comprehensively. As a corollary, this study exposes the importance of detailed anatomical descriptions with the utilitarian purpose of clarifying taxonomy and identifying isolated theropod teeth.
Two distinct morphotypes of the interdental plates can be seen in the specimens referred to the t... more Two distinct morphotypes of the interdental plates can be seen in the specimens referred to the taxon Dilophosaurus wetherilli. The holotype UCMP 37302 and the paratype UCMP 37303, both juvenile individuals, possess fully fused and subrectangular interdental plates with an anteroposterior axis of elongation and straight ventral margins of the plates. On the other hand, the juvenile specimen TMM 43646-1 and the adult individual UCMP 77270 display separated interdental plates that are subquadrangular to subrectangular, with a long axis directed ventrodorsally and strongly "V-shaped" ventral margins ([42], pers. obs.). As far as we know, such variability of interdental plates is unique among theropods and cannot be explained by ontogeny, therefore the existence of two taxa of Dilophosaurus in the Kayenta Formation, as previously suggested by [83], seems highly plausible to us. In fact, a second species of Dilophosaurus, D. "breedorum" was named by Welles and Pickering [117] based on the specimen UCMP 77270 in a controversial paper, but the name does not follow the condition of the ICZN to be recognized as valid (see http://theropoddatabase.blogspot.com.ar/2010/05/pickerings-taxa-6-dilophosaurus.html for more information). UCMP 77270 consists of an incomplete skull and skeleton discovered in 1964 that was initially referred to a larger specimen of D. wetherilli [118] then thought to be a new genus closely related to D. wetherilli [83]. Despite the fact that some differences between UCMP 77270 and the type specimens were noted by Welles and Pickering [117], and later by Tykoski [42] and Irmis [119], the scientific literature only recognizes the existence of one species of
Scientific reports, 2013
The non-avian saurischians that have associated eggshells and embryos are represented only by the... more The non-avian saurischians that have associated eggshells and embryos are represented only by the sauropodomorph Massospondylus and Coelurosauria (derived theropods), thus missing the basal theropod representatives. We report a dinosaur clutch containing several crushed eggs and embryonic material ascribed to the megalosaurid theropod Torvosaurus. It represents the first associated eggshells and embryos of megalosauroids, thus filling an important phylogenetic gap between two distantly related groups of saurischians. These fossils represent the only unequivocal basal theropod embryos found to date. The assemblage was found in early Tithonian fluvial overbank deposits of the Lourinhã Formation in West Portugal. The morphological, microstructural and chemical characterization results of the eggshell fragments indicate very mild diagenesis. Furthermore, these fossils allow unambiguous association of basal theropod osteology with a specific and unique new eggshell morphology.
Acta Palaeontologica Polonica, 2014
EAVP Extraordinary Meeting, Brussels, Belgium. (February 9th-14th, 2009), 2009
EAVP Extraordinary Meeting, Brussels, Belgium. (February 9th-14th, 2009), 2009
72nd Annual Meeting Society of Vertebrate Paleontology, Raleigh, USA. (October 17-20, 2012), 2012
56th Annual Symposium of Vertebrate Palaeontology and Comparative Anatomy, Dublin, Ireland. (September 2nd-6th 2008)., 2008
Uploads
Papers by Christophe Hendrickx