Vegetative and reproductive organs of Late Cretaceous Pinus spp. from Esqueda, Sonora, Mexico
Por:
Huerta Vergara A.R., Cevallos-Ferriz S.R.S.
Publicada:
1 dic 2018
Resumen:
The fossil record of conifers in Mexico is poor and scattered. It is
restricted to the Mesozoic in northern Mexico and becomes younger
towards Southern and Central Mexico. This paper describes and identifies
Pinaceae conifers from Late Campanian (+/- 72 Ma) rocks near the town of
Esqueda, Sonora. Interpretations are based on leaves and an ovulate cone
preserved as impression/compression fossils with small permineralized
areas. Morphological characters observed in the leaves (leaf type,
margin, venation, apex, base and phyllotaxy), branch (leaf scars), and
leaf anatomy (permineralized areas), as well as the morphology of a
female cone (ovuliferous scales), suggest affinity of the new fossil
material with Pinus sp. A single vascular bundle in the leaves suggests
affinity to the section Strobus, while the dorsal umbo with conical
processes in the cone scales relates them to the section Pinus.
Considering that the new fossils grew in the same type of plant, they
would represent the earliest and most complete Pinaceae of Mexico and
would confirm the presence of a third section within the genus,
previously documented only from the Middle Eocene of Canada. Thus, they
extend the historical and geographical range of Pinaceae in America. (C)
2018 Elsevier B.V. All rights reserved.
Filiaciones:
Huerta Vergara A.R.:
Posgrado en Ciencias de la Sostenibilidad, UNAM, Instituto de Ingeniería, Av. Universidad 3000, Col. CU-UNAM, Del. Coyoacán, CDMX, 04510, Mexico
Cevallos-Ferriz S.R.S.:
Instituto de Geología, UNAM, Departamento de Paleontología, Av. Universidad 3000, Col. CU-UNAM, Del. Coyoacan, CDMX, 04510, Mexico
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