Revised age constraints for Late Cretaceous to early Paleocene terrestrial strata from the Dawson Creek section, Big Bend National Park, west Texas

2018 ◽  
Vol 130 (7-8) ◽  
pp. 1143-1163 ◽  
Author(s):  
Caitlin E. Leslie ◽  
Daniel J. Peppe ◽  
Thomas E. Williamson ◽  
Matthew Heizler ◽  
Mike Jackson ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
National Park ◽  
Big Bend National Park ◽  
West Texas ◽  
Big Bend ◽  
Early Paleocene ◽  
Age Constraints

Fire regimes of the piñon–juniper woodlands of Big Bend National Park and the Davis Mountains, west Texas, USA

2009 ◽  
Vol 39 (6) ◽  
pp. 1236-1246 ◽  
Author(s):  
H.M. Poulos ◽  
R.G. Gatewood ◽  
A.E. Camp
Keyword(s):  
National Park ◽  
Fire Regime ◽  
Fire Regimes ◽  
Climatic Conditions ◽  
Tree Regeneration ◽  
Big Bend National Park ◽  
Fire Scar ◽  
West Texas ◽  
Big Bend ◽  
Davis Mountains

While piñon woodlands cover much of arid North America, surprisingly little is known about the role of fire in maintaining piñon forest structure and species composition. The lack of region-specific fire regime data for piñon–juniper woodlands presents a roadblock to managers striving to implement process-based management. This study characterized piñon–juniper fire regimes and forest stand dynamics in Big Bend National Park (BIBE) and the Davis Mountains Preserve of the Nature Conservancy (DMTNC) in west Texas. Mean fire return intervals were 36.5 and 11.2 years for BIBE and DMTNC, respectively. Point fire return intervals were 150 years at BIBE and 75 years at DMTNC. Tree regeneration in west Texas piñon–juniper woodlands occurred historically during favorable climatic conditions following fire years. The presence of multiple fire scars on our fire-scar samples and the multicohort stands of piñon suggested that low intensity fires were common. This study represents one of the few fire-scar-based fire regime studies for piñon–juniper woodlands. Our results differ from other studies in less topographically dissected landscapes that have identified stand-replacing fire as the dominant fire regime for piñon–juniper woodlands. This suggests that mixed-severity fire regimes are typical across southwestern piñon forests, and that topography is an important influence on fire frequency and intensity.

Tyrannosauroid dinosaurs from the Aguja Formation (Upper Cretaceous) of Big Bend National Park, Texas

2012 ◽  
Vol 103 (3-4) ◽  
pp. 471-485 ◽  
Author(s):  
Thomas M. Lehman ◽  
Steven L. Wick
Keyword(s):  
National Park ◽  
Upper Cretaceous ◽  
Frontal Bone ◽  
Adult Size ◽  
Unique Combination ◽  
Big Bend National Park ◽  
West Texas ◽  
Big Bend ◽  
Large Predators ◽  
Sagittal Crest

ABSTRACTRare remains of tyrannosauroid dinosaurs from the Aguja Formation in West Texas indicate the presence here of a relatively gracile species, comparable in form and adult size to Appalachiosaurus or subadult albertosaurines, Gorgosaurus and Albertosaurus. Histologic analysis of one of the specimens indicates that the Aguja tyrannosaur attained an adult size substantially smaller than adult albertosaurines (700 kg, 6·5 m body length). The frontal bone is narrow with a wide orbital slot and a bipartite joint for the postorbital, features thought to be diagnostic of Albertosaurinae; but there is a tall sagittal crest and reduced parietal wedge separating the frontals on the midline, features thought to be diagnostic of Tyrannosaurinae. The tall sagittal crest may be a synapomorphy of Tyrannosaurinae, and the Aguja tyrannosaur is herein referred to that clade. However, the unique combination of character states exhibited by the frontal prevents confident attribution to any known species. The Aguja tyrannosaur provides further evidence that North American Campanian tyrannosauroids were remarkably diverse for such large predators, and that each species was apparently endemic to a relatively small geographic province.

LATE CRETACEOUS WOODY DICOTS FROM THE AGUJA AND JAVELINA FORMATIONS, BIG BEND NATIONAL PARK, TEXAS, USA

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 83-120 ◽  
Author(s):  
E. A. Wheeler ◽  
T. M. Lehman
Keyword(s):  
Late Cretaceous ◽  
National Park ◽  
Sedimentary Facies ◽  
Flood Plain ◽  
Big Bend National Park ◽  
Flood Plains ◽  
Big Bend ◽  
Stratigraphic Succession ◽  
Subordinate Role

Angiosperm woods occur throughout Upper Cretaceous (84–66 million years old) continental strata of Big Bend National Park, Texas, USA. Vertebrate remains occur along the same stratigraphic levels, providing a rare opportunity to reconstruct associations of sedimentary facies, wood remains, and vertebrate remains. The wood collection sites span a vertical stratigraphic succession that corresponds to an environmental transect from poorly-drained coastal salt- or brackish water swamps to progressively better drained freshwater flood-plains lying at increasingly greater distance from the shoreline of the inland Cretaceous sea and at higher elevations. The eight dicot wood types of the Aguja Formation differ from the five types of the Javelina Formation, paralleling a change from a fauna dominated by duckbill and horned dinosaurs to a fauna dominated by the large sauropod, Alamosaurus. These woods increase the known diversity of Cretaceous woods, and include the earliest example of wood with characteristics of the Malvales. The lower part of the upper shale member of the Aguja contains numerous narrow axes, some seemingly in growth position, of the platanoid/ icacinoid type, and of another wood that has a suite of features considered primitive in the Baileyan sense. Duckbill dinosaur remains are common in the facies with these woods. In contrast to other Cretaceous localities with dicot wood, Paraphyllanthoxylon is not common. Dicotyledonous trees are most abundant at the top of the Aguja and the lower part of the Javelina Formations in sediments indicating well-drained inland fluvial flood-plain environments. One locality has logs and insitu stumps, with an average spacing of 12–13 metres between each tree, and trees nearly 1 metre in diameter. To our knowledge this is the first report of anatomically preserved in situ Cretaceous dicot trees. Javelinoxylon wood occurs at all levels where remains of the giant sauropod Alamosaurus occur. The vertebrate faunas of the late Cretaceous of New Mexico and Texas are said to comprise a ʻsouthernʼ fauna distinct from the ʻnorthern faunaʼ of Alberta and Montana. The wood remains are consistent with such provincialism. It has been suggested that dicots were not commonly trees in the late Cretaceous of the northern part of the western interior of North America. The Big Bend woods provide direct evidence for dicot trees having more than a subordinate role in Cretaceous vegetation at lower latitudes. Most of the dicot wood types of Big Bend are characterized by high proportions of parenchyma, over 50% in one type. Whether these high proportions of parenchyma are correlated with the higher CO2 levels of the Cretaceous and /or the pressures exerted by aggressive browsing by large dinosaur herbivores is unknown.

Hadrosaurian dinosaurs from the Maastrichtian Javelina Formation, Big Bend National Park, Texas

2016 ◽  
Vol 90 (2) ◽  
pp. 333-356 ◽  
Author(s):  
Thomas M. Lehman ◽  
Steven L. Wick ◽  
Jonathan R. Wagner
Keyword(s):  
New Species ◽  
Great Plains ◽  
National Park ◽  
Northern Great Plains ◽  
Single Specimen ◽  
Big Bend National Park ◽  
West Texas ◽  
Big Bend ◽  
A New Species ◽  
Specific Identity

AbstractRare remains of hadrosaurian dinosaurs previously reported from the Maastrichtian Javelina Formation of West Texas had been attributed tentatively to either Edmontosaurus or Kritosaurus. Three recently recovered specimens include substantial skull parts and postcranial skeletal elements sufficient to recognize three distinct hadrosaurs. Two species are found in the lower part of the Javelina Formation; one of these is identified as Kritosaurus sp., confirming the earlier referral of specimens to this taxon. The most complete of these specimens combines features thought to be diagnostic of both K. navajovius Brown, 1910 and ‘Naashoibitosaurus’ ostromi Hunt and Lucas, 1993 and exhibits some unique attributes such that its specific identity remains uncertain. A second species, documented by a single specimen found near the base of the Javelina Formation, is inadequate to confidently identify but appears to represent a ‘solid-crested’ saurolophine with frontals having upturned processes along the midline, similar to those that brace the posterior side of the narial crest in Saurolophus. A third hadrosaur is represented at a bonebed in the uppermost part of the Javelina Formation. Its remains are sufficient to justify designation as a new species ?Gryposaurus alsatei. The skull roof elements are similar to those in species of Gryposaurus, and although no parts of the narial crest are preserved, the bordering elements indicate that ?G. alsatei was a ‘flat-headed’ saurolophine. Referral of ?G. alsatei to Gryposaurus would constitute a significant temporal range extension for the genus into late Maastrichtian time, and if correct, this long-lived lineage of hadrosaurs persisted nearly to the end of Cretaceous time in West Texas. ?G. alsatei was a contemporary of Edmontosaurus, the sole terminal Cretaceous hadrosaur in the northern Great Plains region, and neither possessed the ornate narial crest that characterized many earlier hadrosaurs.

The gray vireo (Vireo vicinior Coues; Aves: Vireonidae) wintering in the Big Bend region, west Texas

1971 ◽  
Vol 49 (6) ◽  
pp. 953-955
Author(s):  
Jon C. Barlow ◽  
Roland H. Wauer
Keyword(s):  
National Park ◽  
Wintering Grounds ◽  
Big Bend National Park ◽  
West Texas ◽  
Big Bend ◽  
Northwestern Mexico ◽  
Big Bend Region

The gray vireo, which was previously known only to winter in southwestern Arizona and northwestern Mexico, is reported as wintering in small numbers in Big Bend National Park, west Texas. This area is 450 mi east of the previously known wintering grounds.

scholarly journals Revised age constraints for Late Cretaceous to early Paleocene terrestrial strata from the Dawson Creek section, Big Bend National Park, west Texas

2017 ◽  
Author(s):  
Caitlin E. Leslia ◽  
Daniel J. Peppe ◽  
Thomas E. Williamson ◽  
Matthew Heizler ◽  
Mike Jackson ◽  
...  
Keyword(s):  
Great Plains ◽  
National Park ◽  
Upper Cretaceous ◽  
Northern Great Plains ◽  
Magnetic Carrier ◽  
Mammalian Fauna ◽  
Big Bend National Park ◽  
Magnetic Carriers ◽  
Big Bend ◽  
Age Constraints

We analyzed samples for paleomagnetism, 40Ar/39Ar detrital sanidine ages, and mammalian fauna to produce a precise chronostratigraphic framework for the Upper Cretaceous to lower Paleocene Dawson Creek section of Big Bend National Park. Prior to this work, the absolute age and duration of the Upper Cretaceous Aguja and Javelina Formations and Paleocene Black Peaks Formation were relatively poorly constrained. The documented polarity zones can be correlated to C32n-C31n, C29r, and C27r of the geomagnetic polarity time scale (GPTS) with three hiatuses spanning more than 1.5 myr each. Rock magnetic analyses indicate that the dominant magnetic carrier in the Aguja and Black Peaks Formations is titanomagnetite while the Javelina Formation has varying magnetic carriers including hematite, magnetite, and maghemite. An overprint interval surrounding the K-Pg boundary suggests the primary magnetic carrier, titanohematite, was likely reset by burial and/or overlying basaltic flows. These are the first independent age constraints for the Cretaceous-Paleocene strata at the Dawson Creek section that determines the age and duration of deposition of each formation in the section, as well as the age and duration of multiple unconformities through the succession. As a result, these age constraints can be used to reassess biostratigraphic and isotopic correlations between the Big Bend area and other Cretaceous-Paleogene (K-Pg) basins across North America. Based on this new data, we reassign the age of the mammalian fauna found in the Black Peaks Formation from the Puercan to the Torrejonian North American Land Mammal age. Our age constraints show that the dinosaur fauna in the Javelina Formation in the Dawson Creek area is latest Maastrichtian and restricted to C29r. Thus, the Javelina dinosaur fauna is correlative to the Hell Creek Formation dinosaur fauna from the Northern Great Plains, indicating differences between the faunas are not due to differences in age and providing support for the hypothesis of provinciality and endemism in dinosaur communities in the late Maastrichtian. Further, the age constraints indicate that the previously documented mid-Maastrichtian and late Maastrichtian greenhouse events were rapid (<200 kyr) and correlate closely with climate events documented in the marine record.

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