An incomplete skeleton of a small tetrapod from the Upper Pennsylvanian of New Mexico represents a new genus and species of varanopid eupelycosaur named Eoscansor cobrensis. This skeleton is from the Cobrean (Virgilian) interval of the El Cobre Canyon Formation in the Cañon del Cobre of Rio Arriba County, New Mexico. Eoscansor is a small varanopid distinguished from other varanopids primarily by the unique structure of its manus and pes metapodials and phalanges. Diverse aspects of its anatomy indicate that Eoscansor was a climber, and possibly arboreal, the oldest such tetrapod now known. These features include: claw, phalangeal, and metapodial adaptations indicative of grasping, clinging, and climbing ability; equivalence of high claw curvature and limb length between the fore- and hind limbs; body mass per SVL within the range of extant climbing lizards; very low tibia length/femur length ratio; and a low center of gravity to facilitate an inclined surface-hugging posture.

A large sample of previously undescribed specimens of the rare hedgehog (Erinaceidae) Ocajila Macdonald, 1963, allows for a more complete and detailed description of the dentition of this genus. Previously, only the single (type) species, Ocajila makpiyahe Macdonald, 1963, had been described and limited to fewer than five specimens. The new material has allowed for the recognition of two new species, Ocajila macdonaldi from the Whitneyan of Montana, and Ocajila rasmusseni from the Arikareean of Montana. In addition, an indeterminate species is recognized from the Orellan of Montana, representing the earliest occurrence of the genus.

The Eastern American Toad, Anaxyrus americanus americanus (Holbrook, 1836) is an ubiquitous and geographically wide-ranging subspecies of eastern North America. As such, it also varies geographically in several of its life history traits. A statewide examination of its gonadal cycles and body size-age relationships in Pennsylvania revealed a conformity to contemporary latitudinal patterns associated with these life history traits. Likewise, these very responses to spatial differences in climate, we proffer, predispose the Eastern American Toad to climate-change related shifts in timing of reproduction in Pennsylvania. Such a change, depending upon the reproductive response to climate change by Fowler's Toad, Anaxyrus fowleri (Hinckley, 1882), could result in an increased likelihood of hybridization, a phenomenon with significant evolutionary implications.

Buffalo nut (Cervantesiaceae; Pyrularia pubera Michx.) is a unique facultative hemiparasitic species that can reproduce clonally or sexually. Fragmented population stands of buffalo nut in Pennsylvania, USA, represent the northern–most range of distribution of the species. These leading–edge populations could be the originators for new stands expected to arise as climate change shifts this species' native range further north. When observing an isolated stand of buffalo nut, it is impossible to be sure if individual trees are clones of a common parental plant or the product of sexual reproduction. Our study represents the first attempt to use population genetic methodologies to determine the genetic relatedness of individual plants in fragmented stands, and to assess the genetic diversity of native buffalo nut populations in North America. Our study used microsatellite markers to compare genetic variation in samples from populations in Pennsylvania to samples collected in other populations in the northern end of its range (i.e., West Virginia, Kentucky, and Virginia). We found 1) that trees could not be located at most sites, and 2) that Pennsylvania populations are largely clonal with little genetic diversity among locations within the state (∼200 km²) relative to populations sampled in Kentucky and Virginia. We provide best practice suggestions for conservation of this species.