Early Oligocene chinchilloid caviomorphs from Puerto Rico and the initial rodent colonization of the West Indies.

By their past and present diversity, rodents are among the richest components of Caribbean land mammals. Many of these became extinct recently. Causes of their extirpation, their phylogenetic affinities, the timing of their arrival in the West Indies and their biogeographic history are all ongoing debated issues.

Lumbosacral Transitional Segments: An Interventional Spine Specialist's Practical Approach.

The presence of a lumbosacral transitional vertebrae (LSTV) should prompt a more detailed preprocedural evaluation of the vertebral column to accurately determine spinal levels. An LSTV should prompt the use of corroborating intraprocedural imaging to verify morphology. The most important factors in treating lumbosacral transitional segments are communication among treating physicians to ensure segmental enumeration consistency and associated appropriate patient treatment.