Letteratura scientifica selezionata sul tema "Red Deer Cemetery (Red Deer, Alta.)"

More than 60 specimens of a fossil liverwort gametophyte have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality near Red Deer, Alta. They closely resemble thalli of extant Riccia and have been assigned to the genus Ricciopsis Lundblad. Thalli are linear and prostrate, with smooth margins and a distinct dorsal sulcus. Dichotomous branching occurs in a single plane. Ribbonlike segments reach lengths as great as 55.0 mm, with up to seven dichotomies. Width is typically 1.5–2.0 mm, but abrupt constrictions and dilations are sometimes present proximal to dichotomies. The latter feature distinguishes this fossil from known fossil and living Ricciaceae, and thus it is referred to a new species, Ricciopsis speirsae sp.nov. Liverworts are not common in the fossil record. Ricciopsis speirsae is the first ricciaceous fossil to be described from North America and the first of Paleocene age worldwide. The specimens are found in a layer of lacustrine claystone, scattered among remains of a free-floating lemnaceous plant. Both the geologic setting and the associated fossils indicate that the environment of deposition was a shallow oxbow lake. Key words: Ricciaceae, Riccia, Ricciopsis, liverwort, Paleocene, fossil.

Six kinds of angiosperm compression fossils are described from the Paskapoo Formation (Late Paleocene) at Joffre Bridge near Red Deer, Alta. Pistillate inflorescences with attached carpels, folliculate infructescences, seeds, seedlings, leaves, and shoots arc all assigned to Joffrea speirsii gen. et sp. nov. Crane and Stockey. Evidence for treating the different organs under a single binomial includes attachment of inflorescences and leaf petioles to long and short shoot systems, morphological intermediates between carpels and follicles, follicles preserved expelling seeds, seeds preserved during germination, stages in seedling development, similarity between seedling and adult foliage, and constant field association. Joffrea is similar in many respects to the widespread Upper Cretaceous and early Tertiary fossil Nyssidium arcticum (Heer) Iljinskaja. Comparison of Joffrea to the extant genera Cercidiphyllum Siebold et Zuccarini, Trochodendron Siebold et Zuccarini, and Tetracentron Oliver indicates a close relationship to Cercidiphyllum; and Joffrea is interpreted as an extinct representative of the family Cercidiphyllaceae. The fossil material clarifies morphological interpretations of the pistillate reproductive structures in extant Cercidiphyllum. The probable staminate inflorescences of Joffrea, are also similar to extant Cercidiphyllum. They are budlike and composed of 10–20 bracts, some of which have stamens in their axils. Pollen has not been recovered from the anthers. Pistillate inflorescences developed from axillary buds on the short shoots and were probably wind-pollinated. The production of numerous small winged seeds, epigeal germination, and the preservation of large numbers of in situ seedlings suggest that Joffrea speirsii and similar extinct Upper Cretaceous and early Tertiary species may have been "weedy" plants capable of rapidly colonizing open floodplain habitats.