ASIA

Omitting some mammals described earlier in the section on Middle Jurassic, there are three possible occurrences of Late Jurassic mammals in Asia. One of these is at Shar Teeg, Mongolia (figure 2.12). An account of this locality, its setting, and fauna is given by Gubin and Sinitza (1996).

The fauna and flora are quite diverse, including a large assemblage of insects. Vertebrates include fishes, labyrintho-donts, turtles, crocodilians, and dinosaurs, as well as one mammal. Overall, the biota most resembles that of the Late Jurassic, with some suggestion of an affinity to Chinese faunas of that age. The strata are predominantly of lacustrine origin. The mammal from Shar Teeg is Tego-therium gubini, thought by its describer to represent a new higher category of therian mammals (Tatarinov, 1994), but considered by others to be a docodontan (e.g., Hopson, 1995; Kielan-Jaworowska et al. 2000; see also chapter 5).

The other two Late Jurassic mammal sites of Asia are both in China. Shilongzhai is in Sichuan Province, in the Shaximiao Formation. The age of the unit is not settled. An early report (Chow and Rich, 1982) indicated that it is Callovian, or Middle Jurassic; in rough agreement, Lucas (1996) placed the Shaximiao Formation within his "Tuo-jiangian" vertebrate faunachron, which he considers to be of late Middle Jurassic age (Bathonian-Callovian). However, another recent report considers the unit to be Upper Jurassic, probably Oxfordian or Kimmeridgian (Wang, Clemens, et al., 1998).

The first mammal to be described from Shilongzhai is Shuotherium dongi, which documents a previously unknown group of mammals (see chapter 6). The primary three lower molar cusps are arranged in the typical triangular pattern characteristic of therians, but the heel is developed on the front of the tooth, rather than the back as in tribosphenic mammals (Chow and Rich, 1982). Later discoveries of shuotheres include another species from Shilongzhai, S. shilongi, as many as three species of Shuotherium from the Jurassic of England, and upper molars referable to that genus (Sigogneau-Russell, 1998; Wang, Clemens, et al., 1998). The British occurrence is well established as late Bathonian and, given the apparent presence there of one of the same species (Shuotherium dongi) as at Shilongzhai, it may provide support for a Middle Jurassic correlation for the Shaximiao Formation. A mammal reported from the Kota Formation, India, by Prasad and Manhas (1999), as "shuothere-like" may belong to Docodonta (G. V. R. Prasad, pers. comm.).

The other possible Late Jurassic mammal site in China is Jianshan Wash, in Xinjiang Province (figure 2.4). The site is in the Shishuguo Formation, which was first (Chow and Rich, 1984a) reported to be Middle or Upper Jurassic and later (Dong, 1993) referred to the Upper Jurassic. The mammal described from Jianshan Wash is Klamelia zhaopengi, an "amphilestid triconodont" said to be rather similar to Gobiconodon of the Early Cretaceous (see Kielan-Jaworowska and Dashzeveg, 1998, and comments under Early Cretaceous, later).

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