The common pyrothere of Salla, Bolivia (Deseadan, late Oligocene) is described as a new species, Pyrotherium macfaddeni. It is distinguished by its small size (linear dimensions but two-thirds those of Pyrotherium romeroi) and pi-shaped upper premolars. Recovery at Salla of the first known calcaneum of Pyrotherium permits the description and analysis of the proximal tarsus. It is distinctive by the pronounced dorsoventral compression of the calcaneal tuber and similar flattening of the astragalar trochlea, concavity of the ectal facet of the calcaneum, and extreme reduction of contact between the calcaneum and the cuboid. These derived characters were not seen in any other mammal examined except the embrithopod Arsinoitherium from the Tertiary of Africa. Whether this is due to common ancestry or the unusual mode of locomotion used by these animals (graviportal and plantigrade) remains to be seen. This more complete study of the tarsus of Pyrotherium fails to support the proposed relationship of pyrotheres with the Xenungulata.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 24 • No. 2