942 



EOCENE AND OLIGOCENE TITANOTHERES OF MONGOLIA 



relatively less elongate than in the typical Menodus 

 giganteus of South Dakota. It is also inferior in 

 size and relatively less elongate than the type of 

 Menodus mongoliensis of the Gobi Desert, described 

 and figured above. The estimated measurements 

 are as follows: Anteroposterior, 116 millimeters; trans- 

 verse, 62 millimeters; breadth-length index, 45. The 

 very pronounced external cingulum is comparable 

 with that of the typical Menodus, but the breadth- 

 length index shows that it is relatively shorter and 

 broader than the extreme type of Menodus, such as 

 Menodus mongoliensis. 



Figure 795. — Titanotheres of Rumelia, in the Balkan Peninsula; of Tran- 

 sylvania, in southeastern Hungary; and of Bohemia 



A, Paratype of Menodus? rumelicus Toula, 1892, pp. 6-8, figs. 3, 4. Second inferior molar of the right 

 side. Length 80 millimeters, breadth 42 mUlimeters, height 32 millimeters. Discovered at Eajali, 

 the same locality as that of the type (B), but belonging to a different individual. After cast, Am. 

 Mus. 17603. 



B, Type of Menodus? rumelicus Toula, 1892, pp. 5-8, figs. 1, 2. Third lower molar of the right jaw, 

 discovered near Kajali, northwest of Burgas on the Jambol-Burgas Railroad, eastern Rumelia. 

 After cast (Am. Mus. 17602) from original in the National Musetmi of Vienna. Length 93 milli- 

 meters, breadth 43 millimeters; described by the author as closely resembling in its dimensions Menodus 

 (Titanotherium or Bronioiherium) proutii Leidy. Toula described in 1896 (p. 922, fig. 3) a symphysis 

 of the lower jaw from the same locality, referring it to the same species, Menodus? rumelicus. 



C, Type of Titanotherium bohemicum Kiernlk, 1913, pi. 63, figs. 1-4. Fragment of right lower jaw con- 

 taining mj. Original in National Museum of Prague; cast. Am. Mus. 14449. Locality somewhat 

 doubtful; attributed (op. cit., p. 1223) to " Stisswasserkalke von Tuchofitz Oder diesen entspre- 

 chende Bildungen." Distinguished as follows (p. 1219): "Die Begriindung der neuen Spezies 

 beruht also nicht auf der Verschiedenheit in der Provenienz der europSischen Funde, sondern auf 

 den tatsacUichen Unterschieden in den Dimensionen und der ganzen Beschaffenheit des Zahnes." 

 Length 109 millimeters, breadth 50 millimeters. 



All one-third natural size. Compare type of Brachydiaslematlierium Iransilvanicum Bockh and Maty, 

 found in the neighborhood of AndrishSza (Siebenbiirgen), Transylvania, southeastern Hungary, "am 

 linken Qfer des N4dosbaches." (See PI. LXX and fig. 100 of the present monograph.) 



SURVIVING EMBOLOTHERES OF MONGOLIA 



The Oligocene titanotheres of Mongolia described 

 and figured above are those discovered in the seasons 

 of 1922 and 1923. The seasons of 1924 and 1925 

 closed with the discovery of two new and highly fossilif- 

 erous Oligocene horizons, the Ulan Gochu and the 

 Baron Sog. The fossil fields were shut off by civil war 

 in 1926 and 1927. In 1928 extensive collections were 

 made, establisliing the overlying Baron Sog formation 

 as a rich balucliithere horizon, with titanotheres 

 nearly extinct, and the underlying Ulan Gochu for- 

 mation as rich in the giant surviving 

 titanotheres herewith described as em- 

 bolotheres. 



Subfamily EMBOLOTHERIINAE Osborn, 1929 ' 



One of the most surprising results of 

 the Fifth Central Asiatic Expedition, of 

 the season of 1928, under the leadership 

 of Roy Chapman Andrews and Walter 

 Granger, was the discovery of an entirely 

 new type of titanothere, to which the ge- 

 neric name Emboloiherium is given in refer- 

 ence to the unique structure of the forward 

 portion of the cranium. The name is 

 derived from the Greek eju/3oXi7, "battering 

 ram." 



As the brontothere used its horns in toss- 

 ing, the embolothere used its horns for 

 battering, assaulting, attacking, charging, 

 and tossing. Hence the name "battering- 

 ram-nosed titanothere " seems appropriate. 

 From the'front part of the face there arises 

 a completely novel single bony horn com- 

 posed of elongated and uplifted nasal 

 bones; these bones are supported on a firm 

 base of the frontals and maxUlaries. In 

 the genotypic species, Ernboloiherium an- 

 drewsi, the nasal horn rises to a height of 

 28 inches (fig. 797, C) and expands very 

 broadly at the summit into a rugose bony 

 prominence, on the under surface of which 

 is an upward extension of the anterior 

 nares. This single nasal protuberance is 

 totally different in structure from the 

 paired frontonasal bony horns of all pre- 

 viously known titanotheres, as shown by 

 comparison with the frontonasal horns in 

 the juvenile skull of Brontops hrachyce- 

 pJialus (fig. 385, p. 453) or in the adult skull 

 of Brontotherium platyceras (figs. 457-460, 

 pp. 551, 552; PL CLXXXIX). THs 

 profound structural difference was not 

 realized until the juvenile skull of E. 



1 Osborn, H. F., Emboloiherium gen. nov. of the TJlan Gochu, 

 Mongoliar Am. Mus .Novitates No. 353, 20 pp., May 30, 1929. 



