This mass extinction affected ammonites and trilobites, as well as jawed vertebrates, including tetrapod ancestors. These fins evolved into legs of the first tetrapod land vertebrates, amphibians. These fins evolved into the legs of the first tetrapod land vertebrates, amphibians. The fins evolved into the legs of the first tetrapod land vertebrates, amphibians. The African coelacanth genome provides insights into tetrapod evolution. A tetrapod (Greek for "four feet") is a vertebrate with limbs (feet). Gruber and Sparks (2015) have observed the first fluorescence in a marine tetrapod (four-limbed vertebrates). There are around 10,000 living species, making them the most varied of tetrapod vertebrates. The combination of basal tetrapod and mammalian features makes it a unique transitional species. Pectoral and pelvic fins have articulations resembling those of tetrapod limbs. "Oligokyphus" were small tetrapod, terrestrial animals. Devonian climate change, breathing, and the origin of the tetrapod stem group. Pharyngeal slits resembling gill slits are transiently present during the embryonic stages of tetrapod development. Still, some extinct tetrapod groups did retain true gills. The tuatara is the only living tetrapod with well-developed gastralia and uncinate processes.