Vertebrate Synonyms

They occur in vertebrate animals throughout the globe, though varying in abundance in different districts and at different times.

Vertebrate host, Athene noctua, Little Owl; invertebrate host, Culex pipiens.

This line of hypothesis and demonstration is typical of the palaeogeographic methods generally - namely, that vertebrate palaeontologists, impressed by the sudden appearance of extinct forms of continental life, demand land connexion or migration tracts from common centres of origin and dispersal, while the invertebrate palaeontologist alone is able to restore ancient coast-lines and determine the extent and width of these tracts.

As regards existing forms of life, the limitations of the class are perfectly well defined and easy of recognition; for although certain groups (not, by the way, whales, which, although excluded in popular estimation from the class, are in all essential respects typical mammals) are exceedingly aberrant, and present structural features connecting them with the lower vertebrate classes, yet they are by common consent retained in the class to which they are obviously most nearly affiliated by their preponderating characteristics.

Considered collectively, mammals, which did not make their appearance on the earth for some time after reptiles had existed, are certainly the highest group of the whole vertebrate sub-kingdom.