PART 2: Paleontology

Kauffman, Erle G.; Powell, J. Dan

doi:10.1130/mem149-p47

Cited by 7 publications

(3 citation statements)

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“…Consideration of inoceramid musculature furthers our understanding of this family’s ligament, as both are intrinsically interdependant. British Jurassic and Cretaceous inoceramids were monomyarian, with a large posteroventral adductor muscle (Kauffman 1968; Kauffman and Powell 1977) (Pl. 7, figs 5–7).…”

Section: Inoceramid Hinge Plate Functional and Ultrastructural Develomentioning

confidence: 99%

“…Retroceramus is described as having a small anterior adductor muscle, making it anisomyarian in form (Cox 1969; Crame 1982). The position of this additional muscle scar in Retroceramus is usually an area of poor preservation in Parainoceramus , but well‐preserved Actinoceramus from the Albian of Folkestone and studies of North American Upper Cretaceous inoceramids (Kauffman 1968; Kauffman and Powell 1977) indicate that the anterior adductor was absent by this time. Therefore, the Inoceramidae had not evolved towards the typical Pterioid monomyarian arrangement (i.e.…”

Section: Inoceramid Hinge Plate Functional and Ultrastructural Develomentioning

confidence: 99%

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A reconsideration of the origins of the ‘typical’ Cretaceous inoceramid calcitic hinge plate in the light of new ultrastructural observations from some Jurassic ‘inoceramids’

Knight¹,

Morris²

2009

Palaeontology

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Marked differences occur between the hinge plates of Jurassic and Upper Cretaceous British 'inoceramid' species. Albian and Upper Cretaceous inoceramids had the poiriform calcite hinge plate with closely spaced resiliifers that is widely associated with this extinct bivalve family. The whole structure was dominated by compressible ligament. Jurassic species, in contrast, had an ultrastructurally less familiar aragonite hinge plate with widely spaced resiliifers and a ligament reminiscent of Isognomon with equally spaced elastic and compressional components. The wider taxonomic relationships of the Inoceramidae still remain uncertain, although the majority of the evidence links the family to the Pterioida. This study, however, suggests that the ancestral inoceramid did not necessarily have a calcitic hinge plate, but rather that a Jurassic 'inoceramid' species could have been developing such a structure via an aragonite precursor. Observations on British Kimmeridgian 'inoceramid' specimens indicate that calcite was being incorporated into the aragonite hinge plate by these times. Structures in the ligamentat of Jurassic species suggest that the fundamental change in mineralogy was initiated by valve architectural modification at the byssal notch, linked to inoceramid epifaunalism. Worldwide poor preservation of Lower Cretaceous inoceramids makes it very difficult to further prove this hypothesis via intermediate evolutionary stages leading to the fully poiriform calcite hinge plate observed in Albian and Upper Cretaceous species of Inoceramidae.

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Section: Inoceramid Hinge Plate Functional and Ultrastructural Develomentioning

confidence: 99%

Section: Inoceramid Hinge Plate Functional and Ultrastructural Develomentioning

confidence: 99%

A reconsideration of the origins of the ‘typical’ Cretaceous inoceramid calcitic hinge plate in the light of new ultrastructural observations from some Jurassic ‘inoceramids’

Knight¹,

Morris²

2009

Palaeontology

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“…Principal references employed for Gulf Coastal Plain bivalves were those of Stephenson (1941Stephenson ( ,1947Stephenson ( ,1952Stephenson ( ,19550, 1956, Young (1963), and unpublished data on the Woodbine and Eagle Ford formations o f E. G. Kauffman and J. D. Powell (personal communication, 1976). In the U nited States Western Interior, bivalve data were taken from Kauffman (1965Kauffman ( , 1967Kauffman ( , 1970Kauffman ( , 1972Kauffman ( , 1975Kauffman ( , 1977, and works in press or in progress), Scott (1970), Twenhofel (1924), Speden (1970), Scott & Cobban (1966), Cobban & Reeside (1952), Hattin (1962Hattin ( , 1965Hattin ( , 1975, and Kauffman & Powell (1977). These data were supplemented by specific data from older works such as those o f Stanton (1893), Meek (1876), and Whitfield (1880) and from numerous colleagues who have kindly contributed their expertise to this project.…”

Section: Ev O Lu Tio N a R Y Rates And Patterns 285mentioning

confidence: 99%

Evolutionary rates and patterns among Cretaceous Bivalvia

Kauffman

1978

Phil. Trans. R. Soc. Lond. B

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Analyses of over 100 lineages of Cretaceous Mollusca, primarily Bivalvia, representing diverse levels of morphological complexity, habitats, and adaptive strategies, clearly show that evolutionary rates (new taxa/unit time; or average taxa duration) vary widely within lineages subjected to changing environmental stresses, and between lineages and/or adaptive strategies subjected to broadly similar sets of environmental parameters through time. Modes of evolution range from gradualistic to punctuated, dependent upon rates and intensity of change in stress, or on levels of ecological opportunity (available ecospace). Extremely rapid rates of species evolution (one sp./0.08 Ma) and abrupt appearance of higher taxa occur during rapid radiations into unoccupied ecospace, and/or during high stress situations affecting whole biotas during short time intervals (e.g. rapid marine regression). Classification and reconstruction of molluscan phylogeny is most difficult over these intervals of geological time. Ecological factors far outweigh purely genetic factors in determining evolutionary rates and patterns among Mollusca, as determined by tests applied to Cretaceous lineages.

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