ORIGINAL ARTICLE
Morphology, affinities and phytogeographic
history of Porosia Hickey in the Cretaceous
and Paleocene of North America and Asia
1 | Florida Museum of Natural History, Gainesville Florida, 32611-7800, USA |
2 | Geological Institute, Russian Academy of Sciences, Pyzhevskii per., Moscow, 119017 Russia |
Online publication date: 2014-06-17
Publication date: 2014-06-17
Acta Palaeobotanica 2014; 54(1): 77–99
KEYWORDS
ABSTRACT
Morphology and anatomy of the extinct angiosperm fruit, Porosia verrucosa (Lesqueruex) Hickey,
are documented in detail based on various modes of preservation including molds, casts, and permineralizations
from more than seventy localities in the late Cretaceous and Paleocene. The fruits are schizocarpic with paired
unilocular, single-seeded mericarps seated on a prominent gynophore with an hypogynous perianth borne on
a long pedicel. The most distinctive feature of these fruits is the regularly spaced cylindrical intrusions over the
surface of the endocarp. These are interpreted to represent oil cavities similar to those common in the fruits
of extant Rutaceae. The oldest known occurrences of P. verrucosa are from the Late Cretaceous (Campanian
to Maastrichtian) of western North America, but the genus traversed Beringia and became widespread in the
Paleocene both in Asia (Kazakhstan, Amur Region, and Koryak Highlands), and North America (Montana, North
Dakota, Wyoming, Colorado, Oregon, Washington, Alberta, Saskatchewan). It extended to the late Paleocene in
the Rocky Mountain and Great Plains region, and appears to have become extinct near the Paleocene-Eocene
boundary.
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