Gram Formation Stratigraphic range: Tortonian ~ | |
---|---|
Type | Formation |
Lithology | |
Primary | Claystone |
Location | |
Coordinates | 55°18′N9°06′E / 55.3°N 9.1°E Coordinates: 55°18′N9°06′E / 55.3°N 9.1°E |
Approximate paleocoordinates | 55°36′N8°06′E / 55.6°N 8.1°E |
Region | Jutland |
Country | Denmark |
Type section | |
Named for | Gram |
The Gram Formation is a geological formation in Gram, Denmark. It preserves fossils dating from the Miocene period. The formation consists of three layers: the glauconite-rich, the Gram Clay, and the Gram sand. The sediments in the formation were deposited in an open marine depositional environment known as the Gram Sea.
Many fossils of new species have been discovered in the formation, including those of the beaked-whale Dagonodum mojnum [1] and the mollusk species Pseudocochlespira gramensis, [2] as well as specimens of better-known species such as Carcharodon megalodon. [3]
Megalodon, meaning "big tooth", is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), during the Early Miocene to the Pliocene. It was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark. However, it is now classified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous. Its genus placement is still debated, authors placing it in either Carcharocles, Megaselachus, Otodus, or Procarcharodon. This is because transitional fossils have been found showing that megalodon is the final chronospecies of a lineage of giant sharks originally of the genus Otodus which evolved during the Paleocene.
Calvert Cliffs State Park is a public recreation area in Lusby, Calvert County, Maryland, that protects a portion of cliffs that extend for 24 miles along the eastern flank of the Calvert Peninsula on the west side of Chesapeake Bay from Chesapeake Beach southward to Drum Point. The state park is known for the abundance of mainly Middle Miocene sub-epoch fossils that can be found on the shoreline.
Otodus angustidens is a species of prehistoric megatoothed sharks in the genus Otodus, which lived during the Oligocene and Miocene epochs about 33 to 22 million years ago. This shark is related to another extinct megatoothed shark, Otodus megalodon.
Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths. They have been found in the Pisco Formation of Peru and the Bahía Inglesa, Coquimbo, and Horcón formations of Chile. Thalassocninae has been placed in both the families Megatheriidae and Nothrotheriidae.
Psephophorus is an extinct genus of sea turtle that lived from the Oligocene to the Pliocene. Its remains have been found in Europe, Africa, North America, and New Zealand. It was first named by Hermann von Meyer in 1847, and contains seven species, P. polygonus, P. calvertensis, P. eocaenus, P. oregonesis, P. californiensis, P. rupeliensis, P. scaldii, and a species discovered in 1995, P. terrypratchetti.
Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 1995. In 2006, it was classified into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 14–15 million years old. Brygmophyseter is thought to have been 7 meters (23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club.
Otodus chubutensis, meaning "ear-shaped tooth of Chubut", from Ancient Greek ὠτ and ὀδούς – thus, "ear-shaped tooth", is an extinct species of prehistoric megatoothed sharks in the genus Otodus, that lived during Oligocene, Miocene, and Pliocene epochs, approximately 28 – 5 million years ago. This shark is considered to be a close relative of the famous prehistoric megatoothed shark, O. megalodon. However, as is the case with O. megalodon, the classification of this species is disputed.
Livyatan is an extinct genus of macroraptorial sperm whale containing one known species: L. melvillei. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel Moby Dick about a white bull sperm whale. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene epoch, about 9.9–8.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, South Africa, and Australia imply that either it or a close relative survived into the Pliocene, around 5 mya, and was present throughout the Southern Hemisphere. It was a member of a group of macroraptorial sperm whales and was probably an apex predator, preying on whales, seals, and so forth. Characteristically of raptorial sperm whales, Livyatan had functional, enamel-coated teeth on the upper and lower jaws, as well as several features suitable for hunting large prey.
Hemipristis serra is an extinct species of weasel shark which existed during the Miocene epoch. It was described by Louis Agassiz in 1843. While today's snaggletooth shark is not very large or dangerous, Hemipristis serra, which lived in the Atlantic Ocean during the Oligocene and Miocene, was considerably larger than its modern-day relative and had much larger teeth. Its total length is estimated to be with 6 metres (20 ft) long. Marks made by the teeth of H. serra are often found on the bones of the manatee Metaxytherium leading some scientists to hypothesize that H. serra specialized in preying on these sirenians. In the Gatun Formation of Panama, H. serra was contemporary with pups of the large lamniform shark Otodus megalodon, and both it and the great hammerhead are theorized to have preyed on the pups of this larger shark due to their presence within the formation.
Carcharodon hubbelli, also known as Hubbell's white shark, is an extinct species of white shark that evolved between 8 and 5 million years ago during the Late Miocene to Early Pliocene epochs. The shark is a transitional species, showing intermediate features between present-day great white sharks and smaller, prehistoric mako sharks. Its fossils have been unearthed in Peru.
Piscobalaena is an extinct genus of cetaceans, which lived from the Middle to Late Miocene epochs in Peru and Florida. Its fossils have been found in the Pisco Formation of Peru and the Bone Valley Formation of Florida. At least some individuals of this diminutive whale were preyed on by the shark C. megalodon.
The Alachua Formation is a Miocene geologic formation in Florida. The claystones, sandstones and phosphorites of the formation preserve many fossils of mammals, birds, reptiles and fish, among others megalodon.
The Temblor Formation is a geologic formation in California. It preserves fossils dating back from the Late Oligocene to the Middle Miocene of the Neogene period. It is notable for the famous Sharktooth Hill deposit.
This list of fossil fishes described in 2019 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes of every kind that were described during the year 2019, as well as other significant discoveries and events related to paleoichthyology that occurred in 2019.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2018.
Alopias palatasi commonly referred to as the serrated giant thresher, is an extinct species of giant thresher shark that lived approximately 20.44 to 13.7 million years ago during the Miocene epoch, and is known for its uniquely serrated teeth. It is only known from such isolated teeth, which are large and can measure up to an excess of 4 centimetres (2 in), equating to a size rivaling the great white shark, but are rare and found in deposits in the East Coast of the United States and Malta. Teeth of A. palatasi are strikingly similar to those of the giant thresher Alopias grandis, and the former has been considered as a variant of the latter in the past. Scientists hypothesized that A. palatasi may have had attained lengths comparable with the great white shark and a body outline similar to it.
This list of fossil reptiles described in 2019 is a list of new taxa of fossil reptiles that were described during the year 2019, as well as other significant discoveries and events related to reptile paleontology that occurred in 2019.
This list of fossil fishes described in 2020 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes of every kind that were described during the year 2020, as well as other significant discoveries and events related to paleoichthyology that occurred in 2020.
Gram Natural History Museum opened in 1976 in Gram in the Southern Jutland area of Denmark. It was located in Gram Palace until it was moved to a site next to the Gram Clay Pit in 2005. Once an independent museum, it became a part of the larger constellation of museums in Southern Jutland known as Museum Sønderjylland.
Dagonodum is an extinct genus of ziphiid cetacean known from Tortonian age marine deposits in the Gram Formation in Denmark. There is only one known species, Dagonodum mojnum.