260 THE AGE OF MAMMALS 



In the trees was found the gibbon-hke ape Pliopithecus. 



The chief mammaUan faunas parallel with Sansan (Fig. 129, 1) are 

 those of the freshwater calcareous deposits of Georgensgniiind (13) in Ba- 

 varia, and of the lignites of Eibiswald, Wies (15), Goriach (16), and Voits- 

 berg (17) in Styria. Of the conditions in Styria, Hilber ' states that in 

 the early Miocene the sea advanced over parts of central and southern 

 Styria, bringing in great southern molluscs with shells of wonderful hue. 

 In the forests monkeys picked tropical fruits from the trees, and great 

 powerful herbivores found abundant sustenance in the valleys, which were 

 always free from snow. The carnivores hunted herds of muntjacs, such 

 as are found in the East Indies to-day. These conditions are comparable 

 with those now existing along the Bay of Tunis, but the temperature of 

 the water of Tunis is not high enough to permit the growth of coral reefs 

 such as flourished in the Miocene seas bordering Styria. 



Stehlin - states that the known distribution of the Suidae in the Middle 

 Miocene is somewhat more extensive than in the Oligocene, Hyotherium 

 and Chcerotherium extending into Austria, while remains of Listriodon have 

 been found even in Asia Minor. During the transition from the Middle to 

 the Upper Miocene (Stehlin, p. 483) the Suidae become impoverished once 

 more; the aberrant migrants (Listriodon, Chcerotherium) disappear, and only 

 the central form Hyotherium, a survivor from the Oligocene ancestors, con- 

 tinues and undergoes further differentiation into the true pigs (Sus), which 

 first appear in the upper stage. The same author (p. 475) believes that 

 America received its Suidae either from Asia or Europe in the Lower 

 Oligocene or even earlier, the Eocene Choeromoridae of France showing 

 more points of affinity with the American Dicotylidae (peccaries) than 

 with any other forms. 



Stage of Simorre and La Grive-Saint-Alban 



This stage is characterized by an advance and by the introduction of a 

 few new forms. 



The lacustrine calcaires de Simorre (Fig. 129, 2a) directly overlie those 

 of Sansan and are distinguished by mammals of more advanced specific 

 stage. For example, the little two-horned Sumatran rhinoceros (Dicero- 

 rhimis simmorrensis) is more progressive tlian its ancestor D. sansaniensis.^ 

 Again, the Pliopithecus of La Grive, as described by Deperet, is a little 

 nearer the gibbon (Hylobates) than that of Sansan. The best kno\\ai 

 mammals of this stage are those found in the fissure deposits, or sidero- 

 lithiques, of La Grive-Saint-Alban (24) (Isere), explored by Jourdan be- 



' Hilber, V., Die sarmatischen Schichten vom Waldhof bei Wetzelsdorf, Graz SW. Milt. 

 Naturwiss. Ver. Steiertnark, Jahr., 1898, No. 33, Graz, 1897, pp. lS3-18t. 



2 Stehlin, H. G., tjber die Geschichte des Suiden-Gebisses, 1899-1900, p. 482. 



' Osborn, H. F., Phylogeny of the Rhinoceroses of Europe. Bull. Amer. Mus. Nat. Hist., 

 Vol. XIII, Art. xix. Dec. 11, 1900, pp. 258-259. 



