scholarly journals INTRASPECIFIC VARIABILITY IN THE EARLY MIOCENE STRUTHIOLARIID GASTROPOD PERISSODONTA AMEGHINOI (IHERING, 1897) FROM TIERRA DEL FUEGO, ARGENTINA

2021 ◽  
Author(s):  
María López Cabrera ◽  
Eduardo Olivero
Keyword(s):  
Intraspecific Variability ◽  
Tierra Del Fuego ◽  
Early Miocene

Peonza: new gastropod genus from the middle Tertiary of Patagonia and Chile

1994 ◽  
Vol 68 (2) ◽  
pp. 279-286 ◽  
Author(s):  
Amalia M. Olivera ◽  
William J. Zinsmeister ◽  
S. Graciela Parma
Keyword(s):  
New Species ◽  
Temporal Distribution ◽  
Late Eocene ◽  
Tierra Del Fuego ◽  
Early Miocene ◽  
Late Oligocene ◽  
Southern Chile ◽  
Santa Cruz ◽  
Two New Species

A new Tertiary gastropod genus, Peonza n. gen., is described, along with two new species, P. torquata from southern Argentina and P. benjamina from southern Chile. These muricacean gastropods, of uncertain familial status, occur in the late Eocene San Julián Formation and in the late Oligocene to early Miocene? Monte León Formation, Santa Cruz Province, Argentina. They also were recorded in the (probably) Oligocene Magellanian beds in Tierra del Fuego, Argentina, and in early Miocene deposits of the Tres Montes region in the Chilean Canals. In spite of the small number of specimens, Peonza n. gen. seems to have had a wide geographic and temporal distribution.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

The Late Oligocene to Early Miocene foredeep basin system evolution of the Northern Apennines (Emilia-Tuscany, Italy): review and new litho- biostratigraphic data

2018 ◽  
Vol 137 (3) ◽  
pp. 396-419 ◽  
Author(s):  
Gianluca Cornamusini Cornamusini ◽  
Paolo Conti Conti ◽  
Anna Maria Bambini Bambini
Keyword(s):  
Northern Apennines ◽  
Early Miocene ◽  
Late Oligocene ◽  
System Evolution ◽  
Basin System

Palaeontology, taxonomic revision and variability of some species of the genus Gassendiceras Bert et al., 2006 (Ammonitina, Upper Barremian) from southeastern Franc

2013 ◽  
Vol 63 (3) ◽  
pp. 355-429 ◽  
Author(s):  
Didier Bert ◽  
Stéphane Bersac ◽  
Gérard Delanoy ◽  
Léon Canut
Keyword(s):  
New Species ◽  
Intraspecific Variability ◽  
Taxonomic Revision ◽  
Two New Species

Abstract Bed-by-bed sampling of twelve Barremian sections in southeastern France from pelagic basin (Vocontian Basin) to neritic platforms (Arc of Castellane, Arc of Nice and Provencal Domain) has enabled the collection of isochronous samples of the ammonite genus Gassendiceras. Three poorly known species of the Toxancyloceras vandenheckei Zone (Upper Barremian) are revised: G. alpinum, G. multicostatum and G. hoheneggeri; two new species are described (G. rebouleti nov. sp. and G. bosellii nov. sp.). The intraspecific variability of particular species was recognised. This variability is between slender peramorphic and robust paedomorphic extreme morphologies, with the presence of all intermediates.

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