Morphological variation in the ear region of pleistocene elephantimorpha (Mammalia, Proboscidea) from central Texas

2011 ◽  
Vol 272 (4) ◽  
pp. 452-464 ◽  
Author(s):  
Eric G. Ekdale
Keyword(s):  
Morphological Variation ◽  
Central Texas

scholarly journals A quantitative assessment of intraspecific morphological variation in Gahagan bifaces from the southern Caddo area and central Texas

2019 ◽  
Author(s):  
Robert Z. Selden ◽  
John E. Dockall ◽  
Morgane Dubied
Keyword(s):  
Morphological Variation ◽  
Quantitative Assessment ◽  
Time Span ◽  
The Other ◽  
Raw Material ◽  
Material Source ◽  
Hunter Gatherers ◽  
Size Discrepancy ◽  
Central Texas ◽  
Intraspecific Morphological Variation

This investigation aggregates intact or reconstructed Gahagan bifaces from the southern Caddo area and central Texas to test the hypothesis that Gahagan biface morphology differs between the regions. The Gahagan bifaces (n = 102) were scanned, then analysed using a novel landmarking protocol and the tools of geometric morphometrics. Results provide a preview of the significant differences in Gahagan biface morphology expressed between the southern Caddo area and central Texas regions. The size discrepancy represents an inversion of current theoretical constructs that posit a decrease in tool size thought to articulate with an increase in distance from the raw material source. It is posited that the contrasting morphologies represent two discrete communities of practise; one (emergent Caddo horticulturalists) where Gahagan bifaces were enlisted primarily for burial and ritualistic activities, and the other (central Texas hunter-gatherers) where Gahagan bifaces were utilised over a longer time span in more practical and utilitarian contexts.

Architecture of Radiolitid Rudist (Mollusca) Shell-Wall Structures and its Phylogenetic Implications

1975 ◽  
Vol 33 ◽  
pp. 686-687
Author(s):  
David H. Sturm ◽  
Bob F. Perkins
Keyword(s):  
Phylogenetic Relationships ◽  
Outer Wall ◽  
Shell Microstructure ◽  
Shell Wall ◽  
Wall Structures ◽  
Phylogenetic Implications ◽  
Cellular Wall ◽  
Superfamily Analysis ◽  
Central Texas

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.

Morphological variation inNepeta nuda L

1982 ◽  
Vol 93 (1-2) ◽  
pp. 71-76
Author(s):  
S. Kokkini ◽  
D. Babalonas
Keyword(s):  
Morphological Variation

Morphological variation of Synedra rumpens Kuetz. var. fragilarioides Grun.

1991 ◽  
Vol 27 (1) ◽  
pp. 139-162
Author(s):  
Hiroshi FUKUSHIMA ◽  
Tsuyako KO-BAYASHI ◽  
Mika KURIHARA ◽  
Harue OHTSUKA
Keyword(s):  
Morphological Variation

Water quality in south-central Texas, 1996-98

Circular ◽  
2000 ◽  
Author(s):  
Peter W. Bush ◽  
Ann F. Ardis ◽  
Lynne Fahlquist ◽  
Patricia B. Ging ◽  
C. Evan Hornig ◽  
...  
Keyword(s):  
Water Quality ◽  
South Central ◽  
Central Texas
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