Buriolestes

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Buriolestes
Temporal range: Carnian
~237–228 Ma
Foto do bloco com o buriolestes Foto Flavio Lopes (Ufrgs).jpg
Block containing the holotype fossil
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Sauropodomorpha
Genus: Buriolestes
Cabreira et al. 2016
Species: B. schultzi
Binomial name
Buriolestes schultzi
Cabreira et al. 2016

Buriolestes (meaning "Buriol's robber") is a genus of early sauropodomorph dinosaurs from the Late Triassic of Brazil. It contains one species, B. schultzi, named in 2016. The type specimen was found alongside a specimen of the lagerpetid dinosauromorph Ixalerpeton.[1]

Description

A color-coded diagram of the skull

Although Buriolestes superficially resembles the predatory theropod dinosaurs, with jaws lined by finely serrated and slightly curved teeth well-adapted to a carnivorous diet, it is in fact an early member of the otherwise-herbivorous Sauropodomorpha, the group that gave rise to the giant sauropods. Characteristically sauropodomorph traits seen in Buriolestes include a downturned jaw tip and a long deltopectoral crest on the humerus. However, Buriolestes also lacks a small head and enlarged nostrils, which are typical among sauropodomorphs, and the medial condyle on the end of its tibia projects backwards, a distinctive feature (autapomorphy) unique to this animal.[1]

In Buriolestes, the shaft of the pubis is straight, in contrast to later sauropodomorphs, where it has been modified into an expanded "apron", theropods, where it forms a "boot", and all ornithischians, where it is reversed and is parallel to the ischium. Additional traits differentiate Buriolestes from both later and contemporary sauropodmorphs: the front expansion (preacetabular ala) of the ilium is relatively tall, the outer edges of the pubis are bevelled, the trochanter of the femur forms a shelf, and the metatarsal of the fifth digit on the foot is relatively long.[1]

Discovery and naming

The holotype specimen, ULBRA-PVT280, was discovered in the Buriol ravine in São João do Polêsine, Brazil. These rocks are part of the Santa Maria Formation, which dates to the Carnian epoch. The specimen consists of a single skeleton preserving parts of the skull, vertebrae, left forelimb, and left hindlimb. Another set of smaller bones is also present, which may belong to a juvenile or a different taxon altogether. Two individuals of Ixalerpeton were also preserved close by.[1]

Additional remains were described in 2018. These include a mostly complete skeleton, CAPPA/UFSM 0035, which preserves a complete skull and most bones apart from tail vertebrae. Additional dinosaur bones from the Buriol locality may also belong to Buriolestes, but their assignment is uncertain. They include a femur (ULBRA-PVT289), a portion of an individual's hip and hindlimbs (ULBRA-PVT056), and a lone axis vertebra (CAPPA/UFSM 0179). These new finds have made Buriolestes among the most complete Triassic dinosaurs known, comparable to Eoraptor, Herrerasaurus, and Coelophysis.[2]

In 2016, the specimen was named Buriolestes after the Buriol family; the suffix -lestes is Greek for "robber". The specific name honours palaeontologist Cezar Schultz.[1]

Classification

A phylogenetic analysis conducted in 2016 affirmed the sauropodomorph affinities of Buriolestes. Part of the phylogenetic tree from the study is shown below.[1]

Dinosauria

Ornithischia

Saurischia

Herrerasauridae

Daemonosaurus

Tawa

Chindesaurus

Eodromaeus

Guaibasaurus

Theropoda

Sauropodomorpha

Buriolestes

Eoraptor

Pampadromaeus

Panphagia

Saturnalia

Chromogisaurus

Pantydraco

Efraasia

Plateosaurus

Five variants of phylogenetic analyses published earlier were used along with the description of the new specimens in 2018. One of these analyses, based on Langer et al. (2017)[3] placed Buriolestes in a clade of early sauropodomorphs, alongside Eoraptor, Panphagia, Pampadromaeus, and Saturnalia. Another analysis, which used the dataset of Buriolestes' original description with the added parameter of implied weighting, placed it as the sister taxon to Eoraptor, with the Buriolestes+Eoraptor clade sister to a clade connecting Panphagia and Pampadromaeus. The other three analyses, which also corresponded to the original description's dataset, agreed with that study's placement of Buriolestes as the single most basal sauropodomorph.[2]

Paleoecology

Teeth

The shape of the teeth of Buriolestes suggest that it was a carnivore which fed on small vertebrates and invertebrates, which provides evidence that sauropodomorphs - and likely all saurischians and dinosaurs as a whole - were ancestrally carnivorous, and that sauropodomorphs, ornithischians, and various groups of theropods independently became herbivorous.[1]

The co-occurrence of Buriolestes and Ixalerpeton parallels the simultaneous presence of dinosaurs and non-dinosaur dinosauromorphs at other sites (such as the Ischigualasto[4] and Chinle[5] Formations), suggesting that, after their initial evolutionary radiation, dinosaurs did not rapidly replace their dinosauromorph precursors.[1]

See also

References

  1. ^ a b c d e f g h Cabreira, S.F.; Kellner, A.W.A.; Dias-da-Silva, S.; da Silva, L.R.; Bronzati, M.; de Almeida Marsola, J.C.; Müller, R.T.; de Souza Bittencourt, J.; Batista, B.J.; Raugust, T.; Carrilho, R.; Brodt, A.; Langer, M.C. (2016). "A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet". Current Biology. 26: 3090–3095. doi:10.1016/j.cub.2016.09.040. PMID 27839975.
  2. ^ a b Müller, Rodrigo T.; Langer, Max C.; Bronzati, Mario; Pacheco, Cristian P.; Cabreira, Sérgio F.; Dias-Da-Silva, Sérgio (15 May 2018). "Early evolution of sauropodomorphs: anatomy and phylogenetic relationships of a remarkably well-preserved dinosaur from the Upper Triassic of southern Brazil". Zoological Journal of the Linnean Society. doi:10.1093/zoolinnean/zly009.
  3. ^ Max C. Langer; Martín D. Ezcurra; Oliver W. M. Rauhut; Michael J. Benton; Fabien Knoll; Blair W. McPhee; Fernando E. Novas; Diego Pol; Stephen L. Brusatte (2017). "Untangling the dinosaur family tree". Nature. 551 (7678): E1–E3. doi:10.1038/nature24011.
  4. ^ Martínez, R.N.; Apaldetti, C.; Alcober, O.A.; Colombi, C.E.; Sereno, P.C.; Fernandez, E.; Malnis, P.S.; Correa, G.A.; Abelin, D. (2013). "Vertebrate succession in the Ischigualasto Formation". Journal of Vertebrate Paleontology. 32 (Supplement 1: Memoir 12: Basal sauropodomorphs and the vertebrate fossil record of the Ischigualasto Formation (Late Triassic: Carnian-Norian) of Argentina): 10–30. doi:10.1080/02724634.2013.818546.
  5. ^ Irmis, R.B.; Nesbitt, S.J.; Padian, K.; Smith, N.D.; Turner, A.H.; Woody, D.; Downs, A. (2007). "A Late Triassic Dinosauromorph Assemblage from New Mexico and the Rise of Dinosaurs". Science. 317 (5836): 358–361. doi:10.1126/science.1143325. PMID 17641198.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Buriolestes&oldid=868474620"
This content was retrieved from Wikipedia : http://en.wikipedia.org/wiki/Buriolestes
This page is based on the copyrighted Wikipedia article "Buriolestes"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA