"A New Species of Heteromyid Rodent from the Middle Oligocene of Northeast Colorado with Remarks on the Skull" by Edwin C. Galbreath is a scientific publication released in the late 1940s. This scholarly work focuses on a newly discovered species of Heteromyid rodent, "Heliscomys tenuiceps", from the Middle Oligocene era in Northeast Colorado. The document includes detailed descriptions and anatomical observations based on fossil evidence, significantly contributing to the understanding of Rodentia evolution during that period. The book provides an in-depth analysis of this new species based on the discovery of its skull and teeth, elaborating on its size, unique features, and anatomical specifics compared to contemporary species. The author discusses the skull's structure, including observations on the nasal, frontal, and lacrimal bones, and presents measurements of the skull and teeth that demonstrate the species' distinctive characteristics. The study ultimately sheds light on the evolutionary lineage of the Heteromyids and suggests that "H. tenuiceps" exhibits traits linking it to both earlier and later rodent forms, making it a significant find in paleontological studies. (This is an automatically generated summary.)