The Javelina Formation is a geological

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

in Texas. Dating has shown that the strata date to the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

stage of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

, approximately 70 to 66.5 million years old. The middle part of the formation has been dated to about 69 million years ago plus or minus 1 million years and the top situated near the

Cretaceous–Paleogene boundary The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of ...

(in the overlying Black Peaks FormationWoodward, H. N. (2005). Bone histology of the sauropod dinosaur Alamosaurus sanjuanensis from the Javelina Formation, Big Bend National Park, Texas.), dated to 66 Ma ago. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. .

Age

The typical age range of the Javelina Formation has been difficult to determine. Only one geological site in the Javelina Formation has thus far yielded the correct rock types for radiometric dating. The outcrop, situated in the middle strata of the formation about 90 meters below the K-Pg boundary and within the local range of ''Alamosaurus'' fossils and below two sites that have yielded ''Quetzalcoatlus'' fossils, was dated to 69.0 plus or minus 0.9 million years old in 2010. Indeterminate

chasmosaurinae Chasmosaurinae is a subfamily of ceratopsid dinosaurs. They were one of the most successful groups of herbivores of their time. Chasmosaurines appeared in the early Campanian, and became extinct, along with all other non-avian dinosaurs, during ...

fossils have also been as well.

Fossil content

Vertebrate paleofauna

Flora

Woody dicots and

angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

have been unearthed in this formation. Plant fossils indicate that this area was a woodland habitat.

References

{{Reflist

* S. L. Wick and T. M. Lehman. 2013. A new ceratopsian dinosaur from the Javelina Formation (Maastrichtian) of West Texas and implications for chasmosaurine phylogeny. Naturwissenschaften * T. M. Lehman and A. B. Coulson. 2002. A juvenile specimen of the sauropod dinosaur Alamosaurus sanjuanensis from the Upper Cretaceous of Big Bend National Park, Texas. Journal of Paleontology 76(1):156-172 * A. R. Fiorillo. 1998. Preliminary report on a new sauropod locality in the Javelina Formation (Late Cretaceous), Big Bend National Park, Texas. In V. L. Santucci & L. McClelland (eds.), National Park Service Geologic Resources Division Technical Report NPS/NRGRD/GRDTR-98/01. National Park Service Paleontological Research Volume 3:29-31 * A. W. A. Kellner and W. Langston. 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas. Journal of Vertebrate Paleontology 16(2):222-231 * D. A. Lawson. 1976. ''Tyrannosaurus'' and ''Torosaurus'', Maestrichtian dinosaurs from Trans-Pecos, Texas. Journal of Paleontology 50(1):158-164 * D. A. Lawson. 1975. Pterosaur from the latest Cretaceous of West Texas: discovery of the largest flying creature. Science 187:947-948 Geologic formations of Texas Maastrichtian Stage of North America Cretaceous geology of Texas Sandstone formations Siltstone formations Mudstone formations Shale formations Conglomerate formations Deltaic deposits Fluvial deposits Lacustrine deposits Fossiliferous stratigraphic units of the United States Paleontology in Texas

Age

Fossil content

Vertebrate paleofauna

Flora

See also

References

Further reading