[dinosaur] Juvenile Daspletosaurus from Late Cretaceous of Alberta (free pdf)

Ben Creisler
[email protected]

A new paper with free pdf:


Jared T. Voris, Darla K. Zelenitsky, François Therrien & Philip J. Currie
(2019)
Reassessment of a juvenile Daspletosaurus from the Late Cretaceous of
Alberta, Canada with implications for the identification of immature
tyrannosaurids.
Scientific Reports 9, Article number: 17801
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1038_s41598-2D019-2D53591-2D7&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=meuQAQ7fWjI5x_TnNJ_ZWPmvkbR-3uI3-z52GNkhEh0&s=IvfB2gOdpekn5l5yp59PTjgIBnxst4CSLKHW6oetuf0&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_s41598-2D019-2D53591-2D7&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=meuQAQ7fWjI5x_TnNJ_ZWPmvkbR-3uI3-z52GNkhEh0&s=9yYiz_e7wcBEf2rVaoITRC4C-9x5f04pCOejpblpGCM&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_s41598-2D019-2D53591-2D7.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=meuQAQ7fWjI5x_TnNJ_ZWPmvkbR-3uI3-z52GNkhEh0&s=anvrEhCLDco8EamufqM3KZl9f3101po4FMKZk2L0yz4&e= 

Daspletosaurus is a large tyrannosaurine found in upper Campanian deposits
of Alberta and Montana. Although several large subadult and adult
individuals of this taxon are known, only one juvenile individual, TMP
1994.143.1, has been identified. This specimen has played a key role in the
idea that juvenile tyrannosaurid individuals are difficult to differentiate
among species. Here the taxonomic affinity of TMP 1994.143.1 is reassessed
in light of a juvenile tyrannosaurine postorbital recently discovered in
the Dinosaur Park Formation of Alberta. Anatomical comparisons and
phylogenetic analyses reveal that TMP 1994.143.1 is referable to the
albertosaurine Gorgosaurus libratus, whereas the new postorbital belongs to
a small juvenile Daspletosaurus. This taxonomic reassignment of TMP
1994.143.1 results in the juvenile ontogenetic stage of Daspletosaurus
being known only from two isolated cranial elements. The new postorbital
provides insights into early Daspletosaurus ontogeny, revealing that the
cornual process developed earlier or faster than in other tyrannosaurids.
Although some ontogenetic changes in the postorbital are found to be unique
to Daspletosaurus, overall changes are most consistent with those of other
large tyrannosaurines. Our results also show that diagnostic features
develop early in ontogeny, such that juveniles of different tyrannosaurid
species are easier to differentiate than previously thought.

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