Phylogenetic Relationships within the Phocoid Pinniped Clade

鳍足类动物是一种重要的海洋哺乳动物，包括海象、海狮和海豹。然而，它们彼此之间以及与其他哺乳动物之间的进化关系仍不清楚。Annalisa Berta博士是脊椎动物古生物学家，研究化石和活鳍足动物的解剖学，目的是重建它们的进化史。她的研究还考虑了化石物种的功能能力，为该群体的行为进化及其从陆地祖先的转变提供了独特的见解。Berta博士打算利用化石的形态学数据继续研究鳍足动物之间的进化关系。目前的项目将集中在海豚身上，它们可能是海象的姐妹群。研究人员将研究俄勒冈州沿海渐新世-中新世的颅骨和后颅骨材料，并评估其运动能力（主要是前肢与后肢的推进力）。这个项目是对先前支持对类耳鳍足类动物（海象、海狮，但不包括海豹）研究的奖项的合理延伸。这项拟议的研究对广大的科学听众有影响。比较解剖学家和脊椎动物动物学家将欢迎从早第三纪化石中获得的新数据，以及对主要哺乳动物群体进化关系的新重建。功能形态学家将从这项研究中寻找对水生栖息地生活的替代适应的关键信息。进化生物学家将把这些发现与最近基于DNA序列数据的结果结合起来，从而对这一值得注意的群体有一个不同寻常的详细了解。

Pinnipeds are an important group of marine mammals, comprising the walruses, sea lions, and seals. Nevertheless, their evolutionary relationships to each other and to other mammals remain unclear. Dr. Annalisa Berta is a vertebrate paleontologist studying the anatomy of fossil and living pinnipeds for the purpose of reconstructing their evolutionary history. Her research also considers the functional capabilities of fossilized species, providing unique insight into the evolution of behavior in the group, and its transformation from terrestrial ancestors. Dr. Berta proposes to continue her investigations into the evolutionary relationships among pinnipeds using morphological data from fossils. The present project will focus on the phocids, a possible sister-group to the walruses. Cranial and post-cranial material from the Oligocene- Miocene of coastal Oregon will be examined, and locomotor capabilities (principally forelimb versus hindlimb propulsion) estimated. This project represents a logical extension of a previous award that supported study of the otarioid pinnipeds (walruses, sea lions, but not seals). The proposed research has implications for a wide scientific audience. Comparative anatomists and vertebrate zoologists will welcome the new data derived from early Tertiary fossils, along with new reconstructions of evolutionary relationships of major mammalian groups. Functional morphologists will look to this study for critical information on alternative adaptations to life in aquatic habitats. Evolutionary biologists will integrate these findings with recent results based on DNA sequence data, resulting in an unusually detailed understanding of this noteworthy group.