摘要
Alilepus longisinuosus sp.nov.系禄丰古猿动物群兔形目的唯一代表。基于自1976年以来采集到的69件标本,本文对新种的特征,特别是在种内的变异作了描述;并将其与华北及欧洲其它地点的翼兔作了比较。研究结果表明,可能由Gobiolagus或Ordolagus进化而来的Alilepus,在中新世晚期有较大的分化;禄丰的翼兔似乎代表该属向南亚现生的Nesolagus进化的一种。
Among the fossil remains found in the lignite at Shihuiba, from the Ramapithecus locality of Lufeng, Yunnan, are specimens of a previously reported member of the fami-ly Leporidae (Qi, 1979; Wu et al., 1981; Qiu et al., 1985). Material of the mammalian order Lagomorpha in the Lufeng collection is quite rich, but contains only one taxon of Palaeolaginae, Alilepus. Based on 69 speecimens collected in the last decade, descrip-tions and comparisons of this leporid are made. Based on the development of P3 a sug-gested relationship of the new species to some other leporids of China is given in this paper.
Alilepus Dice, 1931
Alilepus longisinuosus sp. nov.
(PI. I; Text-figs. 1-5)
TYPE A right mandibular fragment with part of incisor and P3-M2 (IVPP V8131). TYPE LOCALITY Shihuiba, Lufeng County, Yunnan. TYPE LEVEL Baodean, Uppermost Miocene. FURTHER MATERIAL See the Chinese text.
ETYMOLOGY Sinus, Latin-fold, plus long (Latin), a prefix. In allusion to
the long posterointernal fold of P3, and to the tendency toward loss of the bridge to form a long fold on P3.
DIAGNOSIS About the same size as Alilepus annectens. Incisive foramen end-
ing posteriorly on a line with the anterior alveolar border of P2. Anterolingual fold shallow and anterobuccal fold distinct on P2. On P3 bridge connecting the trigonid and talonid weak or absent. Posterointernal fold deep and anteroexternal lobe of tri-gonid weak.
DIFFERENTIAL DIAGNOSIS Alilepus longisinuosus is distinguished from
A. annectens by its smaller average size; more anteriorly ending incisive foramen; and more shallow anterolingual fold and distinct anterobuecal fold of P2. It also differs generally in having a deeper posterointernal fold, poorly developed bridge aud weaker anteroexternal lobe of trigonid on P3; by the absence of an anteroexternal fold on dP3. by the absence of an anterior lobe of trigonid on dP4, and by the presence of only two roots on dP4. A. longisinuosus differs from A. ucrainicus by its large P2 with two ante-rior folds and its long hypostria with rather strong crenulation of P3-M2. It differs from A. lascarevi by its smaller size and weaker bridge of P3, and weaker crenulation in the hypostria of upper molariform teeth. A. longisinuosus differs from Alilepus sp. from Malusteni. Romania by the absence of an anterior fold and by having a well de-veloped anterointernal fold of P3. MEASUREMENTS See the Chinese text.
DESCRIPTIONS The ending of the incisive fonnamen, on a line with the ante-rior alveolar border of P2, can be seen to be more anteriorly placed than that of A. an-nectens as illustrated by Bohlin (1942. p121). The smallest palatal bridge length is about 7.5 mm anteroposteriorly with the posterior border on a line with the lingual side of M1 and the posterior border of the base of zygoma. The palatal foramen is small, posterointernally, there is another smaller foramen. The lower jaw is of the same shape and structure as in A. annectens.
P2 consists of a single lobe with two cement-filled folds on the anterior surface. The anterolingual fold is narrow and swings labially for about one third of the occlusal surface, while the anterobuccal fold is wide and shallow. The former seems to be more shallow and the latter more distinct than that of A. annectens. On P3 the hypo-stria is straight and crosses half or more of the occlusal surface. The walls of the hy-postria are strongly crenulated. P4 and M1 are very alike in morphology with also deep and usually crenulated hypostria. M2 is relatively small and less crenulated. P3 has one anteroexternal, posteroexternal and posterointernal fold. All the folds persist to the base of the shaft and are filled with cement. In 12 out of 34 teeth P3 has a visible anterointernal fold. The bridge linking the trigonid and talonid varies from complete to absent, which is generally weaker than that of A. annectens. In 5 specimens the bridge linking the trigonid with the talonid is nearly disconnected. In 6 teeth the bridge is absent and a long fold between the trigonid and talonid is P resent. The posteroin
出处
《人类学学报》
1986年第1期41-53,108,共14页
Acta Anthropologica Sinica
