Megalolamna

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Megalolamna
Temporal range: Early to Mid Miocene
~24–15  Ma
Megalolamna paradoxodon teeth.png
Fossil teeth from the Dos Bocas Formation, Ecuador
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Lamniformes
Family: Otodontidae
Genus: Megalolamna
Species:
M. paradoxodon
Binomial name
Megalolamna paradoxodon
Shimada et al., 2016

Megalolamna is an extinct genus of lamniform shark that belongs to the family Otodontidae. Its name comes from the similarity of its teeth to those of the extant shark genus Lamna. It is known from the early Miocene Chilcatay Formation of Peru, Oi and O'oshimojo Formations of Japan, and the Jewett Sand Formation of California and Pungo River Formation, North Carolina in the United States, implying a cosmopolitan distribution. The largest specimen is estimated to have measured about 5.1 metres (17 ft) long. [1]

Taxonomy

Life restoration Megalolamna paradoxodon.png
Life restoration

It is considered to be the sister genus of Otodus . The study of Megalolamna's taxonomic relationships also demonstrates the possibility that Otodus needs to include the species sometimes assigned to Carcharocles (i.e., the megatoothed lineage, including megalodon) in order to be monophyletic. [1]

Related Research Articles

<span class="mw-page-title-main">Lamniformes</span> Order of sharks

The Lamniformes are an order of sharks commonly known as mackerel sharks. It includes some of the most familiar species of sharks, such as the great white, as well as more unusual representatives, such as the goblin shark and megamouth shark.

<i>Carcharodon</i> Genus of sharks

Carcharodon is a genus of sharks within the family Lamnidae, colloquially called the "white sharks." The only extant member is the great white shark. The extant species was preceded by a number of fossil (extinct) species including C. hubbelli and C. hastalis. The first appearance of the genus may have been as early as the Early Miocene or Late Oligocene.

<span class="mw-page-title-main">Megalodon</span> Extinct giant shark species from 23 to 3.6 million years ago

Otodus megalodon, commonly known as megalodon, is an extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. O. megalodon was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark, but has been reclassified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous.

<i>Otodus</i> Extinct genus of sharks (fossil)

Otodus is an extinct, cosmopolitan genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name Otodus comes from Ancient Greek ὠτ- and ὀδούς – thus, "ear-shaped tooth".

<i>Otodus angustidens</i> Species of fossil shark

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. The largest individuals were about 11–12 metres (36–39 ft) long. This shark is related to another extinct megatoothed shark, Otodus megalodon.

<i>Otodus chubutensis</i> Species of fossil sharks

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 Early Miocene to Middle Miocene. The largest individuals were about 13.5 metres (44 ft) long. This shark is considered 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.

<span class="mw-page-title-main">Otodontidae</span> Extinct family of sharks

Otodontidae is an extinct family of sharks belonging to the order Lamniformes. Its members have been described as megatoothed sharks. They lived from the Early Cretaceous to the Pliocene, and included genera such as Otodus, including the giant megalodon. Recent studies of the newly described genus Megalolamna indicate that the members of the genus Carcharocles should be reclassified as members of the genus Otodus. The genus Cretalamna which lived from the mid-Cretaceous-Paleogene is believed to be directly ancestral to Otodus, and thus to megalodon.

<i>Livyatan</i> Extinct genus of sperm whale from the Miocene epoch

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, United States (California), South Africa and Australia imply that either it or a close relative survived into the Pliocene, around 5 mya, and may have had a global presence. 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.

<i>Hemipristis serra</i> Species of shark

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 6 metres (20 ft). Marks made by the teeth of H. serra are often found on the bones of the dugong 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.

<i>Otodus auriculatus</i> Extinct species of shark

Otodus auriculatus is an extinct species of large sharks in the genus Otodus of the family Otodontidae, closely related to the sharks of the genus Otodus, and also closely related to the later species megalodon. The largest individuals were about 9.5 metres (31 ft) long. Its teeth were large, having coarse serrations on the cutting edge, and also with two large cusplets. The teeth can reach up to 130 millimetres (5.1 in), and belonged to a large "megatoothed" shark.

<i>Cretalamna</i> Extinct genus of sharks

Cretalamna is a genus of extinct otodontid shark that lived from the latest Early Cretaceous to Eocene epoch. It is considered by many to be the ancestor of the largest sharks to have ever lived, such as Otodus angustidens, Otodus chubutensis, and Otodus megalodon.

<i>Carcharodon hubbelli</i> Extinct species of shark

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. This shark is a transitional species, showing intermediate features between the extant great white shark and the fossil white shark, Carcharodon hastalis. C. hubbelli appears to be geographically restricted to the Pacific Ocean, with fossils of C. hubbelli recovered from Peru, Chile, California, and New Zealand. This exclusive distribution suggests a Pacific origin for the great white shark.

The Jewett Sand Formation is a geologic formation in California, USA. It preserves fossils dating back to the Miocene Epoch of the Neogene period.

<i>Cosmopolitodus</i> Extinct genus of mackerel shark

Cosmopolitodus is an extinct genus of mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene epochs. Its type species is Cosmopolitodus hastalis, the broad-tooth mako. In 2021, Isurus planus was reassigned to the genus, and thus became the second species C. planus. However, some researchers still consider both species of Cosmopolitodus as species of Carcharodon.

This list of fossil fishes described in 2016 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes and other fishes of every kind that have been described during the year 2016, as well as other significant discoveries and events related to paleontology of fishes that occurred in the year 2016. The list only includes taxa at the level of genus or species.

<i>Otodus aksuaticus</i> Extinct species of shark

Otodus aksuaticus is an extinct species of large shark in the family Otodontidae which may represent a transitional species between Otodus obliquus and Otodus auriculatus. They are similar in overall morphology to Otodus obliquus except they have serrations on their cusps and blade. It is sometimes placed in the genus Otodus. It is mainly found in the Ypresian stage of the Eocene epoch. They have been found in the Woodstock Member of the Nanjemoy Formation of Maryland and Virginia and Ypresian sediments in Aktulagay, Kazakhstan as well as the Ypres clay in Belgium and the London Clay in the United Kingdom.

<i>Otodus sokolovi</i> Extinct large shark, lived late Eocene to early Oligocene periods

Otodus sokolovi is an extinct species or chronospecies of large shark in the family Otodontidae which may represent a transitional chronospecies between Otodus auriculatus and Otodus angustidens. They differ from the former with a less curved root and finer serrations and from the latter with more prominent and recurved cusps. Due to the subtle differences, it is sometimes lumped into O. auriculatus. It, along with the rest of Otodus, is sometimes placed in the genus Carcharocles. Due to its similarities with other chronospecies, it is difficult to tell exactly when it arose and went extinct. Generally, it is said to span from the late Eocene to early Oligocene. They are best known from the late Eocene localities around Dakhla, Morocco and Fayum, Egypt but are represented in many deposits of contemporary age. It measured at least 6 metres (20 ft) long.

This list of fossil fish research presented in 2021 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2021.

This list of fossil fish research presented in 2022 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2022.

This list of fossil fish research presented in 2023 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2023.

References

  1. 1 2 Shimada, K.; Chandler, R. E.; Lam, O. L. T.; Tanaka, T.; Ward, D. J. (2016-10-03). "A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the 'megatoothed' clade". Historical Biology. 29 (5): 704–714. doi:10.1080/08912963.2016.1236795. ISSN   0891-2963. S2CID   89080495.