Oxalaia
| Oxalaia | ||||||||||||
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The holotype of Oxalaia : an incomplete premaxillary about 8 inches long . |
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| Temporal occurrence | ||||||||||||
| Upper Cretaceous ( Cenomanium ) | ||||||||||||
| 100.5 to 93.9 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Oxalaia | ||||||||||||
| Kellner et al. , 2011 | ||||||||||||
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Oxalaia is a genus of large theropod dinosaurs in the Spinosauridae family. The only species described is Oxalaia quilombensis . So far only jaw fragments are known.
Naming
Oxalaia is named after the Yorubian god Obatala , while the second part of the species name, quilombensis , is derived from the Portuguese quilombo , "the place where the quilombola live". The quilombola are descendants of former Brazilian slaves who are native to the island of Cajual, where the fossils were found.
description
The total length of Oxalaia is estimated to be about 12 to 14 meters, its weight is estimated to be five to seven tons. This makes it the largest theropod found in Brazil to date and one of the largest known land predators in the history of the earth. It was only surpassed by its relative Spinosaurus and some representatives of the Carcharodontosauridae .
The holotype consists of the incomplete paired, about 20.1 centimeter long intermaxillary bone (premaxillary), with seven tooth sockets . In addition, a fragment of the left upper jaw is assigned to the genus. The entire skull is estimated to be 1.35 meters in length.
Systematics
Oxalaia differs from the African Spinosaurus in the number of teeth on the premaxillary and the distance between the individual teeth. Oxalaia can be differentiated from the Baryonychinae , a subfamily of the spinosaurids, on the basis of the unsawed teeth and the two replacement teeth on the third tooth socket. The latter is unique to a theropod. Oxalaia is counted to the Spinosaurinae . His closest relatives include Spinosaurus and Angaturama, which was also found in Brazil .
Smyth et al. (2020) consider Oxalaia to be a synonym for Spinosaurus aegyptiacus , since, according to the authors, the known material has too few differences to Spinosaurus to justify a position as an independent taxon .
Location
The fossils of Oxalaia were found in northeastern Brazil in the rocks of the Alcântara Formation , which can be dated to the early Upper Cretaceous ( Cenomanian ). Hundreds of other spinosaur teeth are known from the same formation . Some of the teeth may belong to Oxalaia , others may belong to a previously unknown species.
source
- Alexander WA. Waiter; Sergio AK Azevedo; Elaine B. Machado; Luciana B. de Carvalho; Deise DR Henriques: A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil . In: Anais da Academia Brasileira de Ciências . tape 83 , no. 1 , 2011, doi : 10.1590 / S0001-37652011000100006 .
Individual evidence
- ↑ Robert SH Smyth; Nizar Ibrahim; David M. Martill: Sigilmassasaurus is Spinosaurus : a reappraisal of African spinosaurines . In: Cretaceous Research . 2020. doi: 10.1016 / j.cretres.2020.104520 .
