Beesiiwo

Beesiiwo is known from four specimens which were referred to B. cooowuse in 2023 by Fitch et al., (2023). The holotype, USNM 494329 consists of a fragment of a left maxilla, and a left dentary,[1] it was previously assigned to cf. "Hyperodapedon" sanjuanensis by Lucas et al., (2002).[2] The additional specimens, UWGM 7027, UWGM 7028, and TxVP 46037.1, consist of fragments of two right maxillae, and a left maxilla.[1] The authors state that an additional specimen NSM018GFF009.003 (which is currently referred to Oryctorhynchus bairdi by Sues et al., (2020)[3]) has "No unique support for [being] Oryctorhynchus bairdi, and [they] do not consider it a part of O. bairdi. These attributes better align with those found in Beesiiwo cooowuse... [they] suggest it is either a close relative of this taxon or a member of such."[1]

Life reconstruction of Beesiiwo cooowuse by palaeoartist Gabriel Ugueto

The generic name, Beesiiwo (IPA: [bæsiwɒʔ]), is the Arapaho word beesiiwó, which translates to "big lizard" in English. The specific name, cooowuse (IPA: [dʒɒʔwʊɛʔ]), derives from the Arapaho name co’ oowu se’, which refers to the Alcova area of Central Wyoming, an area within traditional Arapaho Tribe land where Beesiiwo was found. The name was created by Fitch's Arapaho coauthors and is intended to honor the Arapaho people, language and continued stewardship of the Earth, as well as counteract a perceived "colonialism" in the form of using scientific names derived from geographical and personal names "given by colonizers" that "honor the colonizer at the expense of First Nations peoples".[1]

Fitch et al., (2023) recovered Beesiiwo in the Hyperodapedontinae subfamily of Hyperodapedontidae, as a sister taxon to Oryctorhynchus bairdi in a phylogenetic analysis. Their results are shown below:[1]