[dinosaur] Aerosteon holotype-associated tooth from an abelisaurid instead

Ben Creisler
[email protected]

A new paper:

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Christophe Hendrickx, Emanuel Tschopp & Martín d. Ezcurra (2019)
Taxonomic identification of isolated theropod teeth: the case of the shed
tooth crown associated with Aerosteon (Theropoda: Megaraptora) and the
dentition of Abelisauridae.
Cretaceous Research (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.cretres.2019.104312&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=bR64OM-aHZhgw8eaLKqVXzj-kd5G9Guy25PrzFkOX1M&s=YXuYpBtmTqSQdvFHFQKVGNNUb6rXvUepAh2wzZycEyI&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_pii_S0195667118303860&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=bR64OM-aHZhgw8eaLKqVXzj-kd5G9Guy25PrzFkOX1M&s=I3vKr-m37DWqy3M2D3lhtUAooQoP_lkZ3-27UO2bOzE&e= 


Shed teeth are usually the most abundant theropod material on a dinosaur
fossil site and are constantly reported in the literature. Although new
quantitative techniques have emerged to identify isolated theropod teeth
with better accuracy, they remain difficult to assign to a certain
family-level or genus-level taxon because of the presence of rampant
homoplasy in their morphology and the lack of thorough descriptions. Here
we test three methods to investigate the phylogenetic position of a tooth
previously considered to be part of the holotype of the megaraptoran
Aerosteon riocoloradensis (MCNA-PV-3137): a cladistic analysis performed on
a dentition-based data matrix scored across 105 theropod species and using
a backbone topology as constraint, as well as discriminant and cluster
analyses conducted on a dataset of non-avian theropod crown measurements.
Even though the cladistic technique appears to be the most reliable method
to investigate the phylogenetic affinities of theropod teeth, we recommend
using the three techniques conjointly to corroborate the identification of
isolated dental material. The results of the cladistic and discriminant
analyses support the assignment of the tooth associated with MCNA-PV-3137
to an abelisaurid theropod. It should therefore be excluded from the
holotype of Aerosteon. A thorough description of the dental anatomy of
Abelisauridae is also provided. The current study is the first to evaluate
different methodological tools to identify isolated theropod teeth. With
the added detailed description of the dental anatomy of Abelisauridae, it
will also assist future authors to investigate the systematic palaeontology
of isolated theropod teeth with more confidence.

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