Cretaceous Terrestrial Ecology:
Angiosperms
(flowering plants) first appeared in the Early Cretaceous and
subsequently underwent a significant evolutionary diversification in
the Late Cretaceous. However, they remained subordinate plants with
respect to the overall plant community.
Conifers
were the predominant large trees of the Cretaceous landscape, the
most common being a relatively primitive group, the araucarian pines.
Also dominant in the Cretaceous forest were the dawn redwood
(Metasequoia) and bald cypress (Taxodium), as well as gingkoes. In
addition, there were small hardwood angiosperm trees, but for the
most part, these did not exceed 10cm in diameter and 5m in height
(Dodson, 1996).
Ferns
were prominent in the Cretaceous, but probably as undergrowth plants
rather than forest trees. Tree ferns and seed ferns formed a forest
middle story. Grasses had not yet evolved, but mosses, fungi, and
scouring rushes were well represented (Lemon, 1993).
The
cycads (gymnosperms) reached their climax at this time. They had
short, stubby trunks, rather like a pineapple in appearance, and a
crown of palm-like leaves (Lemon, 1993).
(Carnegie Museum, 1997) |
The small angiosperm, Araliopsoides is a shrubby forerunner of our modern sycamore or plane tree. Araliopsoides belonged to a great radiation of related plants that made up an important part of the vegetation at middle and high northern latitudes of the earth during the Late Cretaceous. With few exceptions such as the witch hazel, the sweetgum,and the palm tree, most of these angiosperms have left no descendants in the modern world. |
A fossil cycad leaf. A short stubby-trunked gymnosperm that reached its climax during the Cretaceous. It was rather like a pineapple in appearance, and had a crown of palm-like leaves. |
Cretaceous members of the Magnolia Family grew in warm climates where there was little if any seasonal change. Consequently, they would have had evergreen leaves and scattered flowers that appeared over a prolonged interval. Magnolias are another example of a Cretaceous angiosperm that thrived alongside the Ceratopsids. |