Silesauridae

Silesauridae
Temporal range: Middle Triassic—Late Triassic, 245–203 Ma
Life restoration of a Silesaurus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauriformes
Clade: †Silesauridae
Langer et al., 2010

Silesauridae is an extinct clade of dinosauriformes, a group of Triassic reptiles that included early ancestors and relatives of the dinosaurs. The silesaurids were a sister clade to the dinosaurs. The group was named in 2010 by paleontologist Max C. Langer and colleagues from Brazil and Argentina. They defined it as a branch-based clade of all archosaurs closer to Silesaurus opolensis than to either Heterodontosaurus tucki or Marasuchus lilloensis. At the same time, a second group of scientists independently named Silesauridae as a node-based clade consisting of Lewisuchus, Silesaurus, their common ancestor and all its descendants.[1] Currently, both definitions encompass the same group of animals. In a later paper, Nesbitt and colleagues noted that the earlier definition by Langer et al. did not include a diagnosis, and so was not sufficient to create a ranked family-level name according to the ICZN. Therefore, the family Silesauridae is attributed to Nesbitt et al. 2010 while the clade Silesauridae is attributed to Langer et al. 2010.[2]

The fossils range in age from the Anisian to the Norian stages of the Triassic, about 245 to 203 million years ago.[1][3] To date, the members of the Silesauridae are Silesaurus (which lends its name to the family), Asilisaurus, Diodorus, Eucoelophysis, Lewisuchus, Sacisaurus, Technosaurus, Ignotosaurus, Lutungutali and possibly Pseudolagosuchus. The cladogram below follows Kammerer, Nesbitt & Shubin (2012) phylogenetic analysis of basal ornithodirans.[2]

Ornithodira 

Pterosauria


 Dinosauromorpha 
 Lagerpetonidae 

Lagerpeton chanarensis

Dromomeron gregorii

Dromomeron romeri




 Dinosauriformes 

Marasuchus lilloensis

Dinosauria


 Silesauridae 

Lewisuchus/Pseudolagosuchus

Asilisaurus kongwe

Eucoelophysis baldwini

Silesaurus opolensis

Sacisaurus agudoensis

Diodorus scytobrachion











References

  1. 1 2 Nesbitt, Sterling J., Sidor, Christian A., Irmis, Randall B., Angielczyk, Kenneth D., Smith, Roger M.H. and Tsuji, Linda A. (2010) "Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira." Nature 464(7285):95-8 Supplement
  2. 1 2 Kammerer, C. F.; Nesbitt, S. J.; Shubin, N. H. (2012). "The First Silesaurid Dinosauriform from the Late Triassic of Morocco". Acta Palaeontologica Polonica. 57 (2): 277. doi:10.4202/app.2011.0015.
  3. ↑ Langer, M.C., Ezcurra, M.D., Bittencourt, J.S., and Novas, F.E. (2010). "The origin and early evolution of dinosaurs". Biological Reviews 85:55-110. doi:10.1111/j.1469-185X.2009.00094.x
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