Hall Lake Formation | |
---|---|
Stratigraphic range: Late Cretaceous, Campanian–Maastrichtian ~ | |
Type | Geological formation |
Unit of | McRae Group |
Underlies | Jose Creek Member [1] |
Overlies | "Quaternary-Tertiary basalt flows and alluvium" |
Lithology | |
Primary | Mudstone, "shale", sandstone |
Location | |
Coordinates | 33°12′N107°06′W / 33.2°N 107.1°W |
Approximate paleocoordinates | 40°30′N81°06′W / 40.5°N 81.1°W |
Region | New Mexico |
Country | United States |
The Hall Lake Formation, formerly called the Hall Lake Member, is a geological formation in Sierra County, New Mexico preserving Lancian fauna, most notably dinosaurs. It is regarded as a member of the McRae Group, including the Elephant Butte and Staton-LaPoint locales. [2]
While most estimates place it firmly within the Lancian fauna, specifically using taxa such as Compsemys as index fossils to recover a Campanian-Maastrichtian age, [3] Lozinsky et al. (1984) note the presence of basalt flows and alluvium dating to the Quaternary-Tertiary.
It overlooks the Jose Creek Member and is composed of purple and maroon shales. When they meet, it is marked by a basal conglomerate or a color distinction where conglomerate is absent. Various Cenozoic units overly the formation. Where some choose to classify these layers as a member of the McRae Formation, [4] others classify it as a distinct formation in a group of formations. [5]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Genus | Species | Locality | Material | Notes | Images |
---|---|---|---|---|---|
Tyrannosauridae [4] | indet. | Staton-LaPoint |
| Lozinsky et al. (1984) call it indeterminate | |
Tyrannosaurus [6] | T. mcraeensis | Elephant Butte (upper) |
| ||
Alamosaurus [4] [5] | sp. | upper |
| Tentative referral | |
Sauropoda [7] | Possibly from the Jose Creek Member | ||||
Theropoda [7] |
Color key
| Notes Uncertain or tentative taxa are in small text; |
Taxon | Locality | Material | Notes | Images |
---|---|---|---|---|
Triceratops sp. [2] [4] | 2 miles south of Elephant Butte |
| This genus, Torosaurus or a novel taxon | |
Sierraceratops turneri [5] | Elephant Butte (lower) |
| ||
Ceratopsidae [3] | Elephant Butte (upper) |
| A new genus similar to Torosaurus is said to exist above the base of the formation | |
Elephant Butte (lower) | Indeterminate, in abundance | |||
Torosaurus sp. [3] | Elephant Butte (upper)? | |||
Hadrosauridae [3] | cannot be determined | Indeterminate and of unknown origins due to faulting or Quaternary cover | ||
Ankylosauria [4] [7] |
| Possibly from the Jose Creek Member, near identical from UNM-FKK-001P of the Kirtland Formation |
Taxon | Locality | Material | Notes |
---|---|---|---|
Testudinata [2] | Elephant Butte (upper) | ||
Crocodylia [2] | |||
Compsemys [3] | Index fossils suggesting a Lancian age | ||
Bothremydidae [3] |
Genus | Species | Locality | Material | Notes |
---|---|---|---|---|
Araucarites [7] | A. sp. | |||
Cinnamomum [7] | C. sp. | |||
Exnelumbites [8] | E. morphotype 2 | Leaves | A member of Nelumbonaceae | |
Ficus [7] | F. sp. | |||
Phyllites [7] | P. sp. | |||
Sabal [7] | S. sp. | |||
Sabalites [7] | S. sp. | |||
Salix [7] | S. sp. | |||
Sequoia [7] | S. sp. | |||
Tracheophyta [2] | Indeterminate | 2 miles south of Elephant Butte | ||
Viburnum [7] | V. sp. |
Kritosaurus is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard", but is often mistranslated as "noble lizard" in reference to the presumed "Roman nose".
Alamosaurus is a genus of titanosaurian sauropod dinosaurs containing a single known species, Alamosaurus sanjuanensis, from the Maastrichtian age of the Late Cretaceous period in what is now southwestern North America. It is the only known titanosaur to have inhabited North America after the nearly 30-million year absence of sauropods from the North American fossil record and probably represents an immigrant from South America.
The Lance (Creek) Formation is a division of Late Cretaceous rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas. The Lance Formation is Late Maastrichtian in age, and shares much fauna with the Hell Creek Formation of Montana and North Dakota, the Frenchman Formation of southwest Saskatchewan, and the lower part of the Scollard Formation of Alberta.
The Kirtland Formation is a sedimentary geological formation.
The Fruitland Formation is a geologic formation found in the San Juan Basin in the states of New Mexico and Colorado, in the United States of America. It contains fossils dating it to the Campanian age of the late Cretaceous.
The McRae Group is a geological group exposed in southern New Mexico whose strata, including layers of the Hall Lake Formation and Jose Creek Formation, date to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from this unit.
The Javelina Formation is a geological formation in Texas. Dating has shown that the strata date to the Maastrichtian stage of the Late Cretaceous, 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, dated to 66 Ma ago. Dinosaur remains are among the fossils that have been recovered from the formation.
The Almond Formation is a geological formation of Late Cretaceous age in Wyoming. It was deposited in marsh, deltaic, lagoonal, estuarine, and shallow marine environments along the western shore of the Western Interior Seaway. It consists primarily of fine- to medium-grained sandstone, siltstone, shale, and coal. Fossils from the Almond Formation include remains of dinosaurs and plants.
Coahuilaceratops is a genus of chasmosaurine ceratopsian dinosaur that lived during the early Maastrichtian age of the Late Cretaceous epoch, about 71.5 to 70.5 million years ago in what is now northern Mexico. It contains a single species, Coahuilaceratops magnacuerna.
The Crevasse Canyon Formation is a coal-bearing Cretaceous geologic formation in New Mexico and Arizona.
The Ojo Alamo Formation is a geologic formation in New Mexico spanning the Mesozoic/Cenozoic boundary. Non-avian dinosaur fossils have controversially been identified in beds of this formation dating from after the Cretaceous–Paleogene extinction event, but these have been explained as either misidentification of the beds in question or as reworked fossils, fossils eroded from older beds and redeposited in the younger beds.
Ojoceratops is a genus of ceratopsian dinosaur which lived in what is now New Mexico, United States. Ojoceratops fossils have been recovered from strata of the Ojo Alamo Formation, dating to the late Cretaceous period. The type species is Ojoceratops fowleri.
Bravoceratops is a genus of large chasmosaurine ceratopsid dinosaur that lived approximately 70 million years ago, and is known from the Late Cretaceous Javelina Formation in what is now Texas, United States.
Dineobellator is a genus of dromaeosaurid theropod dinosaur that lived in North America during the Late Cretaceous period 68 million years ago. The remains have been found in the Maastrichtian stage of the Naashoibito Member at the Ojo Alamo Formation, New Mexico.
Menefeeceratops is a genus of ceratopsid dinosaur from the Menefee Formation in New Mexico, United States. It is potentially the oldest known member of the ceratopsids, as well as the centrosaurine subfamily, related to animals including Yehuecauhceratops and Crittendenceratops. The type and only species is Menefeeceratops sealeyi, known from a partial, non-articulated skeleton.
Sierraceratops is a genus of chasmosaurine ceratopsian from the Late Cretaceous Hall Lake Formation of New Mexico, United States. The genus contains a single species, Sierraceratops turneri, known from a partial skeleton discovered in 1997.
Bisticeratops is a genus of chasmosaurine ceratopsian from outcrops of the Campanian age Kirtland Formation found in the Bisti/De-Na-Zin Wilderness in northwestern New Mexico, United States. The type and only species is B. froeseorum, known from a nearly complete skull.
The sauropod hiatus is a period in the North American fossil record for most of the Late Cretaceous noted for its lack of sauropod remains. It may represent an extinction event, possibly caused by competition with ornithischian herbivores, habitat loss from the expansion of the Western Interior Seaway, or both. Alternatively, it has been argued that the hiatus represents a decrease in inland deposits that would have effectively preserved the animals, creating the illusion of an extinction. The sauropod hiatus ended shortly before the end of the Cretaceous, with the appearance of Alamosaurus, most likely an immigrant from South America, in the southern parts of North America.