ammonoid

Geologically oldest oysters were epizoans on Early Triassic ammonoids. J.

Furnish and Glenister (1970) described the Permian ammonoid Cyclolobus from the Salt Range.

Through the climatic changes, conodont and ammonoid faunae were initially able to recover very quickly during the Early Triassic as unusually short-lived species emerged.

Attachment of the body to the shell in ammonoids. Pp.

Ammonoids. Abrupt diversification of species and genera occurred in the middle of the Artinskian (Bogoslovskaya 1986).

Analysis of heteromorph ammonoids by differential geometry.

They evolved rapidly and, in some stratigraphic intervals, even somewhat more rapidly than Permian ammonoids. Conodonts also exhibit a broader distribution than Permian ammonoids because they are the only stratigraphically important Permian fossil group that is little affected by provincialism.

A contribution to the knowledge of Upper Devonian ammonoids from the Holy Cross Mts.

Based on the scarce ammonoids found in the middle part of the formation, Dubar and Mouterde (1957) and Suarez-Vega (1974) specify a late Kimmeridgian age (Eudoxus zone), and Ramirez del Pozo (1969) assigns an early Portlandian age to the upper part of the Lastres Fm.

The limestone contains bryozoans brachiopods bivalves gastropods ammonoids trilobites crinoids and conodonts (Kummel and Teichert1970).

(1) Ammonoids have an exceptionally good fossil record.

It was his work in the Canadian Arctic Islands, beginning in 1954, that laid the foundation for his subsequent brilliant career as a paleontologist and biostratigrapher specializing in the now-extinct class of coiled, marine molluscs known as ammonoids.

Coprolites containing ammonoids from the Devonian of New York.

The high diversity of one fossil group, the ammonoids, has fueled efforts to understand the functional morphology of their phragmocones.

(3) Boyajian and Lutz (1992) documented patterns in hierarchical complexity at a smaller scale, within a substructure in the extinct ammonoids. Ammonoids secreted a coiled, chambered shell as they grew, and septa separating the chambers are visible externally in many fossil specimens as curvy lines or sutures [ILLUSTRATION FOR FIGURE 6 OMITTED].