Magnapaulia

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Magnapaulia
Temporal range: Campanian
~74.7  Ma
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Magnapaulia skeleton.jpg
Skeletal diagram
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Ornithopoda
Family: Hadrosauridae
Subfamily: Lambeosaurinae
Tribe: Lambeosaurini
Genus: Magnapaulia
Prieto-Márquez et al., 2012
Type species
Magnapaulia laticaudus
(Morris, 1981)
Synonyms

Lambeosaurus laticaudus
Morris, 1981

Magnapaulia is a genus of herbivorous lambeosaurine hadrosaurid dinosaurs known from the Latest Cretaceous Baja California, of northwestern Mexico. It contains a single species, Magnapaulia laticaudus. [2] Magnapaulia was first described in 1981 as a possible species of Lambeosaurus by William J. Morris, [3] and was given its own genus in 2012 by Prieto-Márquez and colleagues. [2]

Contents

Discovery and naming

Skin impressions, Natural History Museum of Los Angeles County Magnapaulia skin impression.jpeg
Skin impressions, Natural History Museum of Los Angeles County

Between 1968 and 1974, a team of the Natural History Museum of Los Angeles County headed by geologist William J. Morris excavated giant lambeosaurine remains from a site near El Rosario in Baja California. Morris named them Lambeosaurus laticaudus in 1981, based on type specimen LACM  17715, a partial skeleton with partial skull. Morris added a question mark to the front of the generic name to indicate its provisional nature: because no complete crest had been found for his species, and without it a definitive assignment could not be made. From what was known of the skull, he considered it to be most like Lambeosaurus. The specific name is derived from the Latin latus, "broad", and cauda, "tail". Morris interpreted this species as water-bound, due to features like its size, its tall and narrow tail (interpreted as a swimming adaptation), and weak hip articulations, as well as a healed broken thigh bone that he thought would have been too much of a handicap for a terrestrial animal to have survived long enough to heal. [3] Between 1981 and 2012, other authors accepted it as a potential species of Lambeosaurus, [4] suggested it could instead be a species of Hypacrosaurus , [5] [6] or questioned its validity. [6]

In 2012 it was named as a separate genus by Albert Prieto-Márquez, Luis Chiappe, and Shantanu Joshi. The generic name is a combination of the Latin magnus, "large", and the first name of Paul G. Haaga Jr., the president of the board of trustees of the Los Angeles County Museum of Natural History. The 2012 study indicated that the remains had been found in a layer of the El Gallo Formation, dating to the late Campanian, about 73.6 to 73 million years old. The study referred numerous other specimens to the species: LACM 17698, 17699, 17700, 17702–17713, 17716 and 17717; LACM 20873-20876; and LACM 20883-20885. These had been found within a distance of three metres to the holotype and consist of partial skeletons, separate bones and skin impressions from several individuals, varying in size. In 2012 a complete redescription of the body parts was given. [2]

Description

Size of two specimens compared to a human Magnapaulia size comparison.png
Size of two specimens compared to a human

Magnapaulia is noted for its great size and the tall profile of its tail, which had elongated chevrons and vertebral spines like those of Hypacrosaurus . [3] Its size was estimated by its original describer as between 15 m (49.2 ft) and 16.5 m (54.1 ft) long, with a body mass of up to 8  metric tons (8.8  tons). [3] Prieto-Márquez et al. provided a smaller estimate of around 12.5 metres (41 ft), still among the longest ornithischians and representing the largest known lambeosaurine, based on the largest known specimen (LACM 17712) with a humerus estimated at 80.3 cm (2.63 ft) in length. [2]

The redescription of 2012 established two autapomorphies, unique derived traits: the presence of chevrons at the tail base that were four times as long as the vertebral centra; and the possession at the tail base vertebrae of front joint processes, prezygapophyses, the inner bases of which formed a bowl-shaped depression that extended upwards into a deep trough on the front surface of the spine. [2]

Life restoration Magnapaulia laticaudus.jpg
Life restoration

On the vertebral column, from at least the middle of the back to over the middle of the tail, a tall crest of almost continuous height was present formed by spines that were about four times as high as the vertebral centra. [2]

Magnapaulia is among the many hadrosaurids that have preserved skin impressions; the tail of specimen LACM 17712 had large scales up to four centimeters wide that were surrounded by one centimeter-wide hexagonal and rounded scales. [3]

Classification

Tail vertebrae Magnapaulia tail vertebrae.tif
Tail vertebrae
Left premaxilla of the holotype Magnapaulia premaxilla.tif
Left premaxilla of the holotype

In 2012 Magnapaulia was assigned to the Lambeosaurinae. The 2012 study contained a cladistic analysis which found it to be closest to Velafrons , also from Mexico, with this sister species forming a separate southern clade, itself the sister group of a clade of more northern Asian and North-American forms, including Lambeosaurus, Corythosaurus , Hypacrosaurus and Olorotitan . The cladogram below follows this analysis. [2]

See also

Related Research Articles

<span class="mw-page-title-main">Hadrosauridae</span> Extinct family of dinosaurs

Hadrosaurids, or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as Edmontosaurus and Parasaurolophus, was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Late Jurassic/Early Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, and South America.

<i>Corythosaurus</i> Extinct genus of dinosaurs

Corythosaurus is a genus of hadrosaurid "duck-billed" dinosaur from the Late Cretaceous period, about 77–75.7 million years ago, in what is now western North America. Its name is derived from the Greek word κόρυς, meaning "helmet", named and described in 1914 by Barnum Brown. Corythosaurus is now thought to be a lambeosaurine, thus related to Lambeosaurus, Nipponosaurus, Velafrons, Hypacrosaurus, and Olorotitan. Corythosaurus has an estimated length of 7.7–9 metres (25–30 ft) and has a skull, including the crest, that is 70.8 centimetres tall.

<i>Parasaurolophus</i> Hadrosaurid ornithopod dinosaur genus from Late Cretaceous Period

Parasaurolophus is a genus of hadrosaurid "duck-billed" dinosaur that lived in what is now western North America and possibly Asia during the Late Cretaceous period, about 76.9–73.5 million years ago. It was a large herbivore that could reach over 9 metres (30 ft) long and weigh over 5 metric tons, and were able to move as a biped and a quadruped. Three species are universally recognized: P. walkeri, P. tubicen, and the short-crested P. cyrtocristatus. Additionally, a fourth species, P. jiayinensis, has been proposed, although it is more commonly placed in the separate genus Charonosaurus. Remains are known from Alberta, New Mexico, and Utah, as well as possibly Heilongjiang if Charonosaurus is in fact part of the genus. The genus was first described in 1922 by William Parks from a skull and partial skeleton found in Alberta.

<i>Lambeosaurus</i> Hadrosaurid dinosaur genus from Late Cretaceous US and Canada

Lambeosaurus is a genus of hadrosaurid dinosaur that lived about 75 million years ago, in the Late Cretaceous period of North America. This bipedal/quadrupedal, herbivorous dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a mitten. Several possible species have been named, from Canada, the United States, and Mexico, but only the two Canadian species are currently recognized as valid.

<i>Hypacrosaurus</i> Extinct genus of reptiles

Hypacrosaurus was a genus of duckbill dinosaur similar in appearance to Corythosaurus. Like Corythosaurus, it had a tall, hollow rounded crest, although not as large and straight. It is known from the remains of two species that spanned 75 to 67 million years ago, in the Late Cretaceous of Alberta, Canada, and Montana, United States, and is the latest hollow-crested duckbill known from good remains in North America. It was an obscure genus until the discovery in the 1990s of nests, eggs, and hatchlings belonging to H. stebingeri.

<i>Saurolophus</i> Hadrosaurid dinosaur genus from the Late Cretaceous period

Saurolophus is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 66 million years ago. It is one of the few genera of dinosaurs known from multiple continents. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky.

<i>Olorotitan</i> Extinct genus of dinosaurs

Olorotitan was a monotypic genus of lambeosaurine duck-billed dinosaur, containing a single species, Olorotitan arharensis. It was among the last surviving non-avian dinosaurs to go extinct during the Cretaceous–Paleogene extinction event, having lived from the middle to late Maastrichtian-age of the Late Cretaceous era. The remains were found in the Udurchukan Formation beds of Kundur, Arkharinsky District, Amur Oblast, Eastern Russia, in the vicinity of the Amur River.

<i>Eolambia</i> Extinct genus of dinosaurs

Eolambia is a genus of herbivorous hadrosauroid dinosaur from the early Late Cretaceous of the United States. It contains a single species, E. caroljonesa, named by paleontologist James Kirkland in 1998. The type specimen of Eolambia was discovered by Carole and Ramal Jones in 1993; the species name honors Carole. Since then, hundreds of bones have been discovered from both adults and juveniles, representing nearly every element of the skeleton. All of the specimens have thus far been found in Emery County, Utah, in a layer of rock known as the Mussentuchit Member of the Cedar Mountain Formation.

<i>Barsboldia</i> Extinct genus of dinosaurs

Barsboldia is a genus of large hadrosaurid dinosaur from the early Maastrichtian Nemegt Formation of Ömnogöv', Mongolia. It is known from a partial vertebral column, partial pelvis, and some ribs.

<i>Pararhabdodon</i> Extinct genus of dinosaurs

Pararhabdodon is a genus of tsintaosaurin hadrosaurid dinosaur, from the Maastrichtian-age Upper Cretaceous Tremp Group of Spain. The first remains were discovered from the Sant Romà d’Abella fossil locality and assigned to the genus Rhabdodon, and later named as the distinct species Pararhabdodon isonensis in 1993. Known material includes assorted postcranial remains, mostly vertebrae, as well as maxillae from the skull. Specimens from other sites, including remains from France, a maxilla previously considered the distinct taxon Koutalisaurus kohlerorum, an additional maxilla from another locality, the material assigned to the genera Blasisaurus and Arenysaurus, and the extensive Basturs Poble bonebed have been considered at different times to belong to the species, but all of these assignments have more recently been questioned. It was one of the last non-avian dinosaurs known from the fossil record that went extinct during the Cretaceous-Paleogene extinction event.

<i>Nipponosaurus</i> Hadrosaurid dinosaur genus from Late Cretaceous Japan

Nipponosaurus is a lambeosaurine hadrosaur from sediments of the Yezo Group, in Sinegorsk on the island of Sakhalin, which was part of Japan at the time of the species' classification. The type and only species is N. sachalinensis, known only from a single juvenile specimen discovered in 1934 and named in 1936, by Takumi Nagao, with further material of the same individual found in 1937. Since then, the taxon has been largely ignored, and its validity has been doubted, with synonymy with other Asian hadrosaurs or status as a nomen dubium being suggested. Redescriptions from 2004 and 2017, however, have supported recognition as a distinct species. Dating the only specimen has been difficult, but based on associated mollusc taxa, the species likely lived sometime in the upper Santonian or lower Campanian, around 80 million years ago.

<span class="mw-page-title-main">Lambeosaurini</span> Extinct tribe of dinosaurs

Lambeosaurini, previously known as Corythosaurini, is one of four tribes of hadrosaurid ornithopods from the family Lambeosaurinae. It is defined as all lambeosaurines closer to Lambeosaurus lambei than to Parasaurolophus walkeri, Tsintaosaurus spinorhinus, or Aralosaurus tuberiferus, which define the other three tribes. Members of this tribe possess a distinctive protruding cranial crest. Lambeosaurins walked the earth for a period of around 12 million years in the Late Cretaceous, though they were confined to regions of modern-day North America and Asia.

<span class="mw-page-title-main">Lambeosaurinae</span> Extinct subfamily of dinosaurs

Lambeosaurinae is a group of crested hadrosaurid dinosaurs.

<i>Koutalisaurus</i> Extinct genus of dinosaurs

Koutalisaurus is a potentially dubious genus of extinct hadrosaurid dinosaur from the Arenysaurini. It is based on a mostly complete dentary from the Maastrichtian-age Upper Cretaceous Tremp Formation near the town of Abella de la Conca, Lleida, Spain.

<i>Velafrons</i> Extinct genus of dinosaurs

Velafrons is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. It is known from a mostly complete skull and partial skeleton of a juvenile individual, with a bony crest on the forehead. Its fossils were found in the late Campanian-age Cerro del Pueblo Formation, near Rincon Colorado, Coahuila, Mexico. The type specimen is CPC-59, and the type species is V. coahuilensis.

The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of the Late Cretaceous. The chalk was formed by pelagic sediments deposited along the eastern edge of the Mississippi embayment. It is a unit of the Selma Group and consists of the upper Arcola Limestone Member and an unnamed lower member. Dinosaur, mosasaur, and primitive bird remains are among the fossils that have been recovered from the Mooreville Chalk Formation.

<span class="mw-page-title-main">Cerro del Pueblo Formation</span> Geological formation in Mexico

The Cerro del Pueblo Formation is a geological formation in Coahuila, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. The formation is believed to correlate with the Baculites reesidesi and Baculites jenseni ammonite zones, which dates it to 73.63-72.74 Ma.

<i>Augustynolophus</i> Extinct genus of dinosaurs

Augustynolophus is an extinct genus of herbivorous saurolophine hadrosaur dinosaur which was discovered in the Moreno Formation in California, dating to the late Maastrichtian age, making it one of the last dinosaurs known from the fossil record before the Cretaceous–Paleogene extinction event.

<span class="mw-page-title-main">Timeline of hadrosaur research</span>

This timeline of hadrosaur research is a chronological listing of events in the history of paleontology focused on the hadrosauroids, a group of herbivorous ornithopod dinosaurs popularly known as the duck-billed dinosaurs. Scientific research on hadrosaurs began in the 1850s, when Joseph Leidy described the genera Thespesius and Trachodon based on scrappy fossils discovered in the western United States. Just two years later he published a description of the much better-preserved remains of an animal from New Jersey that he named Hadrosaurus.

References

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  2. 1 2 3 4 5 6 7 Prieto-Márquez, A.; Chiappe, L. M.; Joshi, S. H. (2012). Dodson, Peter (ed.). "The lambeosaurine dinosaur Magnapaulia laticaudus from the Late Cretaceous of Baja California, Northwestern Mexico". PLOS ONE. 7 (6): e38207. Bibcode:2012PLoSO...738207P. doi: 10.1371/journal.pone.0038207 . PMC   3373519 . PMID   22719869.
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  5. Evans, David C.; Reisz, Robert R. (2007). "Anatomy and relationships of Lambeosaurus magnicristatus, a crested hadrosaurid dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta". Journal of Vertebrate Paleontology. 27 (2): 373–393. doi:10.1671/0272-4634(2007)27[373:AAROLM]2.0.CO;2. ISSN   0272-4634.
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