The Origin and Evolution of Mammals - Moodle

164 THE ORIGIN AND EVOLUTION OF MAMMALS
(a)
(b)
(c)
Tinodon
Woutersia
Bondesius
pa.d
pr.d
me.d
in North America and Europe, is a typical example.
Hu et al. (1997) described a largely complete spalacotheriid
skeleton from the Early Cretaceous Yixian
Formation of northeastern China (Zhou et al. 2003).
(d)
(e)
M 3
M 4 M 5
M 3 M 4 M 5 M 6
Zhangheotherium
Figure 5.14 Symmetrodontans. (a) Upper molar of Eurylambda in occlusion with two lower molars of the closely related Tinodon, in
bucco-lingual and occlusal views (Crompton and Jenkins 1967). (b) Isolated upper and lower molars of Woutersia butleri in occlusal and lingual
views (Sigogneau-Russell and Hahn 1995). (c) Isolated right lower molar of Bondesius ferox in occlusal, labial, and lingual viens (Bonaparte 1990).
(d) Lower jaw of Zhangheotherium quinquecuspidens in medial view, with enlarged views of upper and lower molars. Length of jaw approx. 2.5 cm
(Hue et al. 1997). (e) Skeleton of Zhangheotherium quinquecuspidens as preserved. Maximum length approx. 13 cm (Hu et al. 1997).
Named Zhangeotherium (Fig. 5.14(d) and (e)), it has
added enormously to the detailed knowledge of a
basal holotherian, and reveals a number of additional
characters shared with the later holotherians.