Although isolated mammalian petrosals often are encountered in the fossil record, few detailed descriptions of these bones exist for extant taxa. As a contribution to that void, isolated petrosals are described in detail for two nine-banded armadillos, Dasypus novemcinctus Linnaeus, 1758, and are placed in the context of the basicranium based on an additional 18 specimens, all from Carnegie Museum of Natural History. Neurovascular structures are reconstructed based on study of serially sectioned fetal specimens from the Anatomisches Instituts in Frankfurt and Heidelberg, Germany. Preliminary comparisons are made with other extinct and extant eutherians that the author has described in recent years. Unexpectedly, quite a few similarities are found between the petrosals of D. novemcinctus and the chiropteran Pteropus livingstonii Gray, 1866, which in light of the divergent phyletic affinities and biologies of these animals are remarkable convergences.

The skull of the Hispaniolan solenodon, Solenodon paradoxus Brandt, 1833, was described in detail by Wible (2008). Missing from that study, however, were original observations on the hyoid apparatus and ossified larynx, because appropriate specimens were not available. A specimen has come to light preserving four isolated hyoid and laryngeal bones, from rostral to caudal as situated in the living animal: the right stylohyal, the left epihyal, the hyoid (fused ceratohyals, basihyal, and thyrohyals), and the ossified thyroid cartilage. These elements are poorly known for most mammals. Consequently, the solenodon elements are described and illustrated, and preliminary comparisons with other lipotyphlans are made. Several features are unique to the solenodon among the studied lipotyphlans, including a ceratohyal oriented mediolaterally rather than craniocaudally and an epiglottic prominence on the rostrodorsal margin of the thyroid.

An associated partial postcranial skeleton is described as the third definitive ornithopod dinosaur record from the Upper Cretaceous Bajo Barreal Formation of central Patagonia, Argentina. Specifically, the specimen was recovered from the uppermost Cretaceous (Campanian—?Maastrichtian) Upper Member of the Bajo Barreal exposed on an ephemeral island in the southeastern portion of Lago Colhué Huapi in southern Chubut Province. Identifiable elements of the skeleton include four incomplete dorsal vertebrae, three partial anterior caudal vertebrae, a middle caudal neural arch, an incomplete posterior caudal vertebra, a dorsal rib fragment, the right calcaneum, and portions of the left metatarsal III and right metatarsal IV. Comparisons with corresponding elements in other ornithischians indicate that the material pertains to a medium-sized, non-hadrosaurid ornithopod. In particular, the morphology of the calcaneum is characteristic of ornithopods of this “grade”. The new discovery augments our understanding of the latest Cretaceous terrestrial vertebrate assemblage of central Patagonia and adds to the generally meager record of ornithischians in the Late Cretaceous of the Southern Hemisphere.

The middle Eocene of North American was an important time in carnivoramorphan evolution, because it is when the order showed increases in diversity taxonomically and ecomorphologically. We describe new fossils of “miacoids” from the Uinta Formation of northeastern Utah, and assess their phylogenetic and paleobiological significance. A new species of Miocyon (Matthew, 1909), is described, Miocyon vallisrubrae, which, in several aspects of lower molar morphology, is intermediate between the smaller Miocyon major (Matthew, 1909) and the larger Miocyon scotti (Wortman and Matthew, 1899). In addition, new well-preserved dental and gnathic specimens of M. scotti are described, along with fragmentary cranial and postcranial remains. The taxonomy of Miocyon is reviewed in light of the new material, which highlights the divergent specializations of the genus. These include an m1 with a relatively broad talonid and an m2 that is large, broad and relatively flat with little difference in height between the trigonid and talonid. These features suggest a shift from a shearing-dominated diet to a greater reliance on grinding. An ecological analogue for the radiation of this lineage among living carnivorans may be the sympatric African species of jackals. The distribution of similar features in Miocyon as well as other “miacoids” suggests an ecomorphologically similar phylogenetic group containing Miocyon, Uintacyon Leidy, 1872, and Vassacyon Matthew, 1909. New specimens from the Uinta Formation are also described of Tapocyon Stock, 1934, Procynodictis Wortman and Matthew, 1899, a new unnamed miacid, and an unnamed small viverravid. These highlight the adaptive diversity of carnivoramorphans during the Uintan North American Land Mammal Age.

The presence of the European land snail, Cepaea hortensis (Müller, 1774), in archaeological deposits indicates its existence in North America before the arrival of post-Columbus European settlers. We address whether this species arrived in North America before Viking explorers. Evidence from cave deposits in St. Elzear de Bonaventura Cave on the Gaspé Peninsula, Quebec, suggests that C. hortensis appeared in North America prior to arrival of the Vikings about 1000 YBP and possibly more than 7850 YBP. The presence of the larger snail species Anguispira alternata (Say, 1816) and Neohelix albolabris (Say, 1817) in cave levels representing tundra to taiga conditions, coupled with their absence as far north as modern taiga, suggests that some large snails may not disperse quickly enough to occupy all favorable habitat made available by warming climates.