Article: Some Lower Cretaceous conifers of the Cheirolepidiaceae from the U.S.A. and England
Publication: Palaeontology
Volume:
20
Part:
4
Publication Date:
January
1978
Page(s):
715
–
749
Author(s):
Joan Watson
Abstract
Five species of Lower Cretaceous conifers assigned to the genera Pseudofrenelopsis Nathorst, Frenelopsis Schenk, and Cupressinocladus Seward of the family Cheirolepidiaceae are redescribed and figured with emended diagnoses. Lectotypes of P. parceramosa (Fontaine) comb. nov., P. varians (Fontaine) comb. nov., and F. ramosissima Fontaine are selected from Fontaine's figured specimens in the collection of the National Museum of Natural History, Smithsonian Institution. A specimen of F. alata (K. Feistmantel) from Texas is redescribed and compared with the Czechoslovakian type material and specimens from Portugal. The holotype of C. valdensis (Seward) from the English Wealden is rediagnosed and its cuticle figured for the first time. P. varians and F. ramosissima are unlike any living conifer in having a very slender core of wood separated from a very thick cuticle by a wide, succulent cortex, indicating that these species were probably shrubby plants rather than large forest trees. They may have been quite small, salt-marsh plants.