Paleocene deposits of the Tullock Member of the Fort Union Formation, Montana, U.S.A., have yielded several new specimens of †Polyodon tuberculata, a taxon previously described from the formation, as well as a new genus and species of sturgeon (Acipenseridae). The three new specimens of †P. tuberculata allow us to revise and to confirm previously reported features of the holotype, as well as to describe other features that were not preserved in the single specimen previously known. For example, we observe that (1) the left and right posttemporals overlie the left and right parietals to meet in the midline, (2) the posttemporal has a deep ventral flange, and (3) the parasphenoid extends farther posteriorly than the parietals. The new sturgeon is fairly small, and not well preserved. It can be distinguished from all other acipenserids by a combination of features, including kite-shaped dorsal scutes bearing a strong median ridge, lateral scutes that vary in shape from rhomboid to irregularly shaped elements, a large triangular scute behind the anal fin, and numerous small rhomboid scales covering the caudal skeleton. It cannot be included in any currently known genus and is here named †Engdahlichthys milviaegis, gen. et sp. nov.
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.