In New Zealand numerous remains of birds are found, chiefly in the Pleistocene strata, associated with Moa bones: such are _Cnemiornis_, the Flightless Pigeon Goose (Fig. 135); _Harpagornis_, a predatory hawk-like bird larger than any existing eagle; and _Aptornis_, an extinct Rail. The sand-dunes, peat bogs, swamps, river alluvium, caves and rock shelters of New Zealand often contain numerous remains of the gigantic Moa birds included in the genera _Dinornis_, _Pachyornis_ and _Anomalopteryx_, of which perhaps the best known are _D. giganteus_, _D. maximus_ (Fig. 136), _D. robustus_, _P. elephantopus_ (Fig. 137), and _A. antiqua_. Some of the species have become so recently extinct that remains of their skin and feathers have been preserved in fissures in the rocks where they were shielded from the influence of air and moisture. The remains of Moa birds are very abundant in some of the localities as at Hamilton in Southland, where, as Hutton estimated, the remains of at least 400 birds were contained within a radius of 25 feet. [Illustration: =Fig. 136--Cnemiornis calcitrans, Owen.= Pleistocene. New Zealand. 1/15th. nat. size (_After Owen_). ] [Illustration:=Fig. 137--Dinornis maximus, Owen. (Great Moa).= Pleistocene and Holocene. New Zealand. Vertical height, 8 ft. Measured along spine, 10 ft. 8 in. (_Nat. Mus. Coll._) ] [Illustration: =Fig. 138--Pachyornis elephantopus, Owen sp.= Pleistocene. New Zealand. About 1/26th. nat. size. (_After Owen_). ] =Mammalia: Early Types.--= _MAMMALIA._--The history of those warm-blooded animals, the mammals, commences in the early part of the Mesozoic period. It was then that the skull began to assume the characters seen in the modern quadrupeds, and their well-formed limb-bones, and fusion of the three bones on each side of the pelvic arch to form the innominate bone, also show relationship to the later types. The earliest ancestral mammalian forms seem to be related to the theromorphic reptiles, predominant in the Permian and Trias. The mammals first to make their appearance were probably related to those of the Monotreme and Marsupial orders. More nearly related to the former is the group of mammals of the Mesozoic period, the Multituberculata. =Multituberculata.--= This group comprises the Triassic _Tritylodon_ (South Africa and Germany); the Upper Jurassic _Bolodon_ (England and United States); the Upper Jurassic to Lower Cainozoic _Plagiaulax_ (England, United States and France); and the Lower Eocene _Polymastodon_ (New Mexico). The molar teeth are ridged longitudinally, and carry numerous tubercles, hence the name of the group, and resemble the deciduous teeth of the Duck-billed Platypus (_Ornithorhynchus_). =Monotremata.--=