# toothless mammal with keratin scales

From teeth to pad: tooth loss and development of keratinous structures in sirenians | Proceedings of the Royal Society B: Biological Sciences » Sirenians are a well-known example of morphological adaptation to a shallow-water grazing diet characterized by a modified feeding apparatus and orofacial morphology. Such adaptations were accompanied by an anterior tooth reduction associated with the… Royalsocietypublishing.org

Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition » Baleen whales (Mysticeti) have an extraordinary fossil record documenting the transition from toothed raptorial taxa to modern species that bear baleen plates, keratinous bristles employed in filter‐feeding. Remnants of their toothed ancestry… Ncbi.nlm.nih.gov

A review and reappraisal of the specific gravities of present and past multicellular organisms, with an emphasis on tetrapods » <em>The Anatomical Record</em> is an anatomy journal publishing new discoveries in the morphological aspects of molecular, cellular, developmental, evolutionary, and systems biology. Anatomypubs.onlinelibrary.wiley.com

Heterochronic truncation of odontogenesis in theropod dinosaurs provides insight into the macroevolution of avian beaks | Proceedings of the National Academy of Sciences » Beaks are innovative structures characterizing numerous tetrapod lineages, including birds, but little is known about how developmental processes i… Pnas.org