Terrestrial Palaeoecology and Global Change

Chapter 4. Palaeoecogeography
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Mongolia (Krassilov, 1982). These allochthonous remains form a morphologic link between
the Jurassic Schizolepis–Pityospermum complex and an extant laricoid genus
Pseudolarix, and are sometimes assigned to the latter (Fig. 40). Pseudolarix kempferi,
a temperate montane species, is the only survivor of the Cretaceous complex of heteroblastic
shoot-dropping conifers that, with the mid-Eocene montane glaciation, conceivably
gave rise both to the deciduous laricoids with persistent spur-shoots and, by a pedomorphic
transformation of heteroblastic shoot system, to the homoblastic piceoids.
c
a
b
e
d
Fig. 40. A precursor of mountain taiga, the Early Cretaceous Pseudolarix forest abundantly represented by
leafy short-shoots and detached cone-scales in the rift valley deposits of Transbaikalia and Mongolia: (a-c)
P. erensis, a modern-type pinaceous conifer growing side by side with (d-f) Swedenborgia, an archaic
voltziaceous conifer probably ancestral to the Pinaceae (Krassilov, 1982).
f