scholarly journals Map and cross sections of coal zones in the Upper Cretaceous Neslen Formation, north-central part of the Westwater 30' x 60' Quadrangle, Grand and Uintah counties, Utah

1991 ◽  
Keyword(s):  
Cross Sections ◽  
Upper Cretaceous ◽  
North Central

Isotaphonomy in concept and practice: an exploration of vertebrate microfossil bonebeds in the Upper Cretaceous (Campanian) Judith River Formation, north-central Montana

Paleobiology ◽  
2017 ◽  
Vol 43 (2) ◽  
pp. 248-273 ◽  
Author(s):  
Raymond R. Rogers ◽  
Matthew T. Carrano ◽  
Kristina A. Curry Rogers ◽  
Magaly Perez ◽  
Anik K. Regan
Keyword(s):  
Upper Cretaceous ◽  
Statistical Tests ◽  
Sampling Strategies ◽  
North Central ◽  
Wetland Ecosystems ◽  
Future Studies ◽  
Size And Shape ◽  
Definition Of ◽  
Central Montana ◽  
Judith River Formation

AbstractVertebrate microfossil bonebeds (VMBs)—localized concentrations of small resilient vertebrate hard parts—are commonly studied to recover otherwise rarely found small-bodied taxa, and to document relative taxonomic abundance and species richness in ancient vertebrate communities. Analyses of taphonomic comparability among VMBs have often found significant differences in size and shape distributions, and thus considered them to be non-isotaphonomic. Such outcomes of “strict” statistical tests of isotaphonomy suggest discouraging limits on the potential for broad, comparative paleoecological reconstruction using VMBs. Yet it is not surprising that sensitive statistical tests highlight variations among VMB sites, especially given the general lack of clarity with regard to the definition of “strict” isotaphonomic comparability. We rigorously sampled and compared six VMB localities representing two distinct paleoenvironments (channel and pond/lake) of the Upper Cretaceous Judith River Formation to evaluate biases related to sampling strategies and depositional context. Few defining distinctions in bioclast size and shape are evident in surface collections, and most site-to-site comparisons of sieved collections are indistinguishable (p≤0.003). These results provide a strong case for taphonomic equivalence among the majority of Judith River VMBs, and bode well for future studies of paleoecology, particularly in relation to investigations of faunal membership and community structure in Late Cretaceous wetland ecosystems. The taphonomic comparability of pond/lake and channel-hosted VMBs in the Judith River Formation is also consistent with a formative model that contends that channel-hosted VMBs were reworked from pre-existing pond/lake assemblages, and thus share taphonomic history.

Decapod crustaceans from the Semilla Sandstone Member, Mancos Shale (Upper Cretaceous), north-central New Mexico

1996 ◽  
Vol 70 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Elizabeth K. Toolson ◽  
Barry S. Kues
Keyword(s):  
New Mexico ◽  
Upper Cretaceous ◽  
Decapod Crustaceans ◽  
North Central ◽  
Mancos Shale ◽  
First Time ◽  
Stratigraphic Range

The decapods Linuparus grimmeri Stenzel, Protocallianassa mortoni (Pilsbry) and Necrocarcinus (Cenomanocarcinus) vanstraeleni (Stenzel)? are described from the middle Turonian Semilla Sandstone Member, Mancos Shale, of north-central New Mexico. The main specimen of P. mortoni is unusually complete, consisting of a complete left first cheliped, parts of other pereiopods, and most of the abdomen. Both L. grimmeri and P. mortoni are reported for the first time from the southern Western Interior. The stratigraphic range of L. grimmeri is extended upward from the upper Cenomanian, and the range of P. mortoni downward from the Campanian.

Upper Cretaceous stratigraphy of the Gebel Somar area, north-central Sinai, Egypt

2009 ◽  
Vol 30 (1) ◽  
pp. 22-34 ◽  
Author(s):  
M.D. Samuel ◽  
A.A. Ismail ◽  
A.I.M. Akarish ◽  
A.H. Zaky
Keyword(s):  
Upper Cretaceous ◽  
North Central ◽  
Area North
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