Barosaurus

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Barosaurus
Temporal range: Late Jurassic (Kimmeridgian), 152–150  Ma
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Barosaurus mount 1.jpg
Mounted skeleton in rearing posture with a juvenile Kaatedocus siberi , American Museum of Natural History
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade:† Sauropodomorpha
Clade:† Sauropoda
Superfamily:† Diplodocoidea
Family:† Diplodocidae
Genus:† Barosaurus
Marsh, 1890
Species:
†B. lentus
Binomial name
†Barosaurus lentus
Marsh, 1890

Barosaurus ( /ˌbæroʊˈsɔːrəs/ BARR-oh-SOR-əs) was a giant, long-tailed, long-necked, plant-eating sauropod dinosaur closely related to the more familiar Diplodocus . Remains have been found in the Morrison Formation from the Upper Jurassic Period of Colorado, Utah, South Dakota, and eastern Wyoming at Como Bluff. It is present in stratigraphic zones 2–5. [1]

Contents

The composite term Barosaurus comes from the Greek words barys (βαρυς) meaning "heavy" and sauros (σαυρος) meaning "lizard", thus "heavy lizard".

Description

Life reconstruction of an individual rearing up to defend itself against a pair of Allosaurus Barosaurus lentus1.jpg
Life reconstruction of an individual rearing up to defend itself against a pair of Allosaurus

Barosaurus was an enormous animal, with some adults measuring about 25–27 m (82–89 ft) in length and weighing about 12–20  metric tons (13–22  short tons). [2] [3] [4] According to Mike Taylor, the 1.37 m (4.5 ft) long vertebra BYU 9024, previously identified as part of the type individual of Supersaurus vivianae , [5] may actually belong to Barosaurus. He suggested that, interpreted as belonging to Barosaurus, the vertebra suggests an animal that was 48 m (157 ft) long and around 66 t (73 short tons) in weight making it one of the largest known dinosaurs, with a neck length of at least 15 m (49 ft). [6] In 2020 Molina-Perez and Larramendi estimated it to be slightly smaller at 45 m (148 ft) and 60 t (66 short tons). [7] However, research presented by Brian Curtice at the Society of Vertebrate Paleontology conference has supported the previous interpretation of BYU 9024 as a Supersaurus vertebra. [8] Despite this, there are other specimens that provide evidence of gigantic Barosaurus individuals which may have been among the longest dinosaurs. One of these is a series of three cervical vertebrae (BYU 3GR/BYU 20815) and the third vertebra is 1110 mm to 1220 mm in length. Dr Mike Taylor and Dr Matt Wedel compared the size of this bone to the same bone in smaller Barosaurus specimens, such as AMNH 6341, and estimated the neck length of the BYU 3GR/20815 Barosaurus at 12.07–15.1 m (39.6–49.5 ft), which would make it one of the longest necks of any dinosaur and indicate a total body length of around 40 m (130 ft). [9] [10] [11] Barosaurus was differently proportioned than its close relative Diplodocus, with a longer neck and shorter tail, but was about the same length overall. It was longer than Apatosaurus , but its skeleton was less robust. [12]

Sauropod skulls are rarely preserved, and scientists have yet to discover a Barosaurus skull. Related diplodocids like Apatosaurus and Diplodocus had long, low skulls with peg-like teeth confined to the front of the jaws. [13]

Size comparison Barosize.svg
Size comparison

Most of the distinguishing skeletal features of Barosaurus were in the vertebrae, although a complete vertebral column has never been found. Diplodocus and Apatosaurus both had 15 cervical (neck) and 10 dorsal (trunk) vertebrae, while Barosaurus had only 9 dorsals. A dorsal may have been converted into a cervical vertebra, for a total of 16 vertebrae in the neck. Barosaurus cervicals were similar to those of Diplodocus, but some were up to 50% longer. The neural spines protruding from the top of the vertebrae were neither as tall or as complex in Barosaurus as they were in Diplodocus. In contrast to its neck vertebrae, Barosaurus had shorter caudal (tail) vertebrae than Diplodocus, resulting in a shorter tail. The chevron bones lining the underside of the tail were forked and had a prominent forward spike, much like the closely related Diplodocus. The tail probably ended in a long whiplash, much like Apatosaurus, Diplodocus and other diplodocids, some of which had up to 80 tail vertebrae. [12]

The limb bones of Barosaurus were virtually indistinguishable from those of Diplodocus. [12] Both were quadrupedal, with columnar limbs adapted to support the enormous bulk of the animals. Barosaurus had proportionately longer forelimbs than other diplodocids, although they were still shorter than most other groups of sauropods. [12] There was a single carpal bone in the wrist, and the metacarpals were more slender than those of Diplodocus. [14] Barosaurus feet have never been discovered, but like other sauropods, it would have been digitigrade, with all four feet each bearing five small toes. A large claw adorned the inside digit on the manus (forefoot) while smaller claws tipped the inside three digits of the pes (hindfoot). [12] [13]

Classification and systematics

Barosaurus is a member of the sauropod family Diplodocidae, and sometimes placed with Diplodocus in the subfamily Diplodocinae. [5] Diplodocids are characterized by long tails with over 70 vertebrae, shorter forelimbs than other sauropods, and numerous features of the skull. Diplodocines like Barosaurus and Diplodocus have slenderer builds and longer necks and tails than apatosaurines, the other subfamily of diplodocids. [12] [13] [5]

Below is a cladogram of Diplodocinae after Tschopp, Mateus, and Benson (2015). [15]

Gordo, Royal Ontario Museum skeleton, Toronto Barosaurus - Sauropod Dinosaur at ROM.jpg
Gordo, Royal Ontario Museum skeleton, Toronto
Diplodocinae

The systematics (evolutionary relationships) of Diplodocidae are becoming better established. Diplodocus has long been regarded as the closest relative of Barosaurus. [12] [13] [16] Barosaurus is monospecific, containing only the type species, B. lentus, while at least three species belong to the genus Diplodocus. [13] Another diplodocid genus, Seismosaurus , is considered by many paleontologists to be a junior synonym of Diplodocus as a possible fourth species. [17] Tornieria (formerly "Barosaurus" africanus) and Australodocus from the famous Tendaguru Beds of Tanzania in eastern Africa have also been classified as diplodocines. [18] [19] With its elongated neck vertebrae, Tornieria may have been particularly closely related to Barosaurus. [18] The other subfamily of diplodocids is Apatosaurinae, which includes Apatosaurus and Supersaurus . [5] The early genus Suuwassea is considered by some to be an apatosaurine, [5] while others regard it as a basal member of the superfamily Diplodocoidea. [20] Diplodocid fossils are found in North America, Europe, and Africa. More distantly related within Diplodocoidea are the families Dicraeosauridae and Rebbachisauridae, found only on the southern continents. [13]

Discovery, naming, and history

One of the original tail vertebrae in multiple views Barosaurus lentus.jpg
One of the original tail vertebrae in multiple views

The first Barosaurus remains were discovered in the Morrison Formation of South Dakota by Ms. Isabella R. Ellerman, postmistress of Postville, and excavated by Othniel Charles Marsh and John Bell Hatcher of Yale University in 1889. Only six tail vertebrae were recovered at that time, forming the type specimen (YPM 429) of a new species, which Marsh named Barosaurus lentus, from the Classical Greek words βαρυς (barys) ("heavy") and σαυρος (sauros) ("lizard"), and the Latin word lentus ("slow"). [21] The rest of the type specimen was left in the ground under the protection of the landowner, Ms Rachel Hatch, until it was collected nine years later, in 1898, by Marsh's assistant, George Reber Wieland. These new remains consisted of vertebrae, ribs, and limb bones. In 1896 Marsh had placed Barosaurus in the Atlantosauridae; [22] in 1898 it was classified by him as a diplodocid for the first time. [23] In his last published paper before his death, Marsh named two smaller metatarsals found by Wieland as a second species, Barosaurus affinis, [24] but this has long been considered a junior synonym of B. lentus. [12] [13] [25]

After the turn of the 20th century, Pittsburgh's Carnegie Museum of Natural History sent fossil hunter Earl Douglass to Utah to excavate the Carnegie Quarry in the area now known as Dinosaur National Monument. Four neck vertebrae, each 1 meter (3 feet) long, were collected in 1912 near a specimen of Diplodocus, but a few years later, William Jacob Holland realized they belonged to a different species. [12] Meanwhile, the type specimen of Barosaurus had finally been prepared at Yale in the winter of 1917 and was fully described by Richard Swann Lull in 1919. [25] Based on Lull's description, Holland referred the vertebrae (CM 1198), along with a second partial skeleton found by Douglass in 1918 (CM 11984), to Barosaurus. This second Carnegie specimen remains in the rock wall at Dinosaur National Monument and was not fully prepared until the 1980s. [12]

Mounted skeleton casts posed depicting a specimen rearing up to protect its young (now considered a Kaatedocus specimen) from an Allosaurus fragilis, American Museum of Natural History Allosaurus and Barosaurus.jpg
Mounted skeleton casts posed depicting a specimen rearing up to protect its young (now considered a Kaatedocus specimen) from an Allosaurus fragilis , American Museum of Natural History

The most complete specimen of Barosaurus lentus was excavated from the Carnegie Quarry in 1923 by Douglass, now working for the University of Utah after the death of U.S. Steel founder Andrew Carnegie, who had been financing Douglass' earlier work in Pittsburgh. Material from this specimen was originally spread across three institutions. Most of the back vertebrae, ribs, pelvis, hindlimb and most of the tail stayed at the University of Utah, while the neck vertebrae, some back vertebrae, the shoulder girdle and forelimb were shipped to the National Museum of Natural History in Washington D.C., and a small section of tail vertebrae ended up in the Carnegie Museum in Pittsburgh. However, in 1929 Barnum Brown arranged for all of the material to be shipped to the American Museum of Natural History in New York City, where it remains today. A cast of this specimen (AMNH 6341) was controversially mounted in the lobby of the American Museum, rearing up to defend its young (AMNH 7530, now classified as Kaatedocus siberi [15] ) from an attacking Allosaurus fragilis. [12]

More recently, more vertebrae and a pelvis were recovered in South Dakota. This material (SDSM 25210 and 25331) is stored in the collection of the South Dakota School of Mines and Technology in Rapid City. [14]

Darren Naish has noted a common error in books of the late 20th century to depict Barosaurus as a kind of brachiosaur-like short tailed sauropod with raphes on its neck and body, and often curving the upper half of its neck downwards into a U-shape, citing it as an example of a Palaeoart meme. [26] [27] This originated with a drawing by Robert Bakker in a 1968 article, in which two Barosaurus appeared to have short tails due to a mix of foreshortening and one obscuring the other.

In 2007, paleontologist David Evans was flying to the U.S. Badlands when he discovered reference to a Barosaurus skeleton (ROM 3670) in the collection of the Royal Ontario Museum in Toronto, where he had recently become a curator. Earl Douglass had excavated this specimen at the Carnegie Quarry in the early 20th century; the ROM acquired it in a 1962 trade with the Carnegie Museum. The specimen was never exhibited and remained in storage until its rediscovery by David Evans 45 years later. He returned to Toronto and searched the storage areas and found many fragments, large and small, of the skeleton. It is now a centrepiece of the ROM's dinosaur exhibit, in the James and Louise Temerty Galleries of the Age of Dinosaurs. [28] At almost 27.5 meters (90 feet) long, the specimen is the largest dinosaur ever to be mounted in Canada. [29] The specimen is about 40% complete. As a skull of Barosaurus has never been found, the ROM specimen wears the head of a Diplodocus. [30] Each bone is mounted on a separate armature so that it can be removed from the skeleton for study and then replaced without disturbing the rest of the skeleton. (See video "Dino Workshop" at reference.) [31] In the rush to put the dinosaur on exhibit within ten weeks of its delivery to Research Casting International in 2500 pieces, not all of the skeletal fragments were mounted. In addition, more bones labeled ROM 3670 are still being found in storage. In future, more may be added to the specimen and it may turn out to be the most complete known.' (See video "Dino Assembly" at reference.) [31] The ROM specimen is nicknamed "Gordo" after Gordon Edmunds, the museum curator who arranged for the skeleton to be brought to the ROM, and who had hoped to display it fully but was unable to. [29] [32] [33] John McIntosh believes that the ROM's skeleton is the same individual represented by four neck vertebrae labeled "CM 1198" in the collection of the Carnegie Museum. [12]

Discoveries in Africa

In 1907, German paleontologist Eberhard Fraas discovered the skeletons of two sauropods on an expedition to the Tendaguru Beds in German East Africa (now Tanzania). He classified both specimens in the new genus Gigantosaurus, with each skeleton representing a new species (G. africanus and G. robustus). [34] However, this genus name had already been given to the fragmentary remains of a sauropod from England. [35] Both species were moved to a new genus, Tornieria, in 1911. [36] Upon further study of these remains and many other sauropod fossils from the hugely productive Tendaguru Beds, Werner Janensch moved the species once again, this time to the North American genus Barosaurus. [37] In 1991, "Gigantosaurus" robustus was recognized as a titanosaur and placed in a new genus, Janenschia , as J. robusta. [38] Meanwhile, many paleontologists suspected "Barosaurus" africanus was also distinct from the North American genus, [12] [13] which was confirmed when the material was redescribed in 2006. The African species, although closely related to Barosaurus lentus and Diplodocus from North America, is now once again known as Tornieria africana . [18] A species of Barosaurus was also allegedly identified from the Kadsi Formation in Zimbabwe in 1987. [39] However, this material is poorly preserved and fragmentary and was not adequately diagnosed as such, and so its referral to Barosaurus is doubtful. It may represent Tornieria. [40]

Paleobiology

Feeding

Skull cast, Natural History Museum of Utah Barosaurus lentus skull salt lake city.jpg
Skull cast, Natural History Museum of Utah

The structure of the cervical vertebrae of Barosaurus allowed for a significant degree of lateral flexibility in the neck, but restricted vertical flexibility. This suggests a different feeding style for this genus when compared to other diplodocids. [41] Barosaurus swept its neck in long arcs at ground level when feeding, which resembled the strategy that was first proposed by John Martin in 1987. [42] The restriction in vertical flexibility suggests that Barosaurus did not primarily feed on vegetation that was high off the ground.

Paleoecology

Barosaurus remains are limited to the Morrison Formation, which is widespread in the western United States between the Great Plains and Rocky Mountains. [12] [13] Radiometric dating agrees with biostratigraphic and paleomagnetic studies, indicating that the Morrison was deposited during the Kimmeridgian and early Tithonian stages of the Late Jurassic Period, [43] or approximately 155 to 148 million years ago. [44] Barosaurus fossils are found in late Kimmeridgian to early Tithonian sediments, [15] around 150 million years old. [43]

Skull possibly belonging to Barosaurus (specimen CM 11255) Diplodocus skull, DNM.jpg
Skull possibly belonging to Barosaurus (specimen CM 11255)

The Morrison Formation was deposited in floodplains along the edge of the ancient Sundance Sea, an arm of the Arctic Ocean which extended southward to cover the middle of North America as far south as the modern state of Colorado. Due to tectonic uplift to the west, the sea was receding to the north, and had retreated into what is now Canada by the time Barosaurus evolved. The sediments of the Morrison were washed down out of the western highlands, which had been uplifted during the earlier Nevadan orogeny and were now eroding. [43] Very high atmospheric concentrations of carbon dioxide in the Late Jurassic led to high temperatures around the globe, due to the greenhouse effect. One study, estimating CO2 concentrations of 1120 parts per million, predicted average winter temperatures in western North America of 20  °C (68  °F ) and summer temperatures averaging 40–45 °C (104–113 °F). [45] A more recent study suggested even higher CO2 concentrations of up to 3180 parts per million. [46] Warm temperatures that led to significant evaporation year-round, along with possible rain shadow effect from the mountains to the west, [47] led to a semi-arid climate with only seasonal rainfall. [43] [48] This formation is similar in age to the Solnhofen limestone Formation in Germany and the Tendaguru Formation in Tanzania. In 1877 this formation became the center of the Bone Wars, a fossil-collecting rivalry between early paleontologists Othniel Charles Marsh and Edward Drinker Cope.

The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as Camarasaurus , Diplodocus , Apatosaurus and Brachiosaurus . Dinosaurs that lived alongside Barosaurus included the herbivorous ornithischians Camptosaurus , Dryosaurus , Stegosaurus and Othnielosaurus . Predators in this paleoenvironment included the theropods Saurophaganax , Torvosaurus , Ceratosaurus , Marshosaurus , Stokesosaurus , Ornitholestes , and [49] Allosaurus accounted for 70 to 75% of theropod specimens and was at the top trophic level of the Morrison food web. [50] Other vertebrates that shared this paleoenvironment included ray-finned fishes, frogs, salamanders, turtles, sphenodonts, lizards, terrestrial and aquatic crocodylomorphs, and several species of pterosaur. Early mammals were present such as docodonts, multituberculates, symmetrodonts, and triconodonts. The flora of the period has been revealed by fossils of green algae, fungi, mosses, horsetails, cycads, ginkgoes, and several families of conifers. Vegetation varied from river-lining forests of tree ferns, and ferns (gallery forests), to fern savannas with occasional trees such as the Araucaria -like conifer Brachyphyllum . [51]

Assistant Curator David Evans mounted the ROM specimen conservatively, with a relatively low head to give the dinosaur moderate blood pressure. [30] The extremely long neck, 10 meters (30 feet) may have developed to enable Barosaurus to feed over a wide area without moving around; it may also have enabled the dinosaurs to radiate excess body heat. Evans suggests that sexual selection might have favored those with longer necks. (See video "Neck Impossible" at reference.) [31]

Related Research Articles

<i>Apatosaurus</i> Sauropod dinosaur genus from Late Jurassic period

Apatosaurus is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax, in 1877, and a second species, A. louisae, was discovered and named by William H. Holland in 1916. Apatosaurus lived about 152 to 151 million years ago (mya), during the late Kimmeridgian to early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, New Mexico, Wyoming, and Utah in the United States. Apatosaurus had an average length of 21–23 m (69–75 ft), and an average mass of 16.4–22.4 t. A few specimens indicate a maximum length of 11–30% greater than average and a mass of approximately 33 t.

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

Supersaurus is a genus of diplodocid sauropod dinosaur that lived in North America during the Late Jurassic period. The type species, S. vivianae, was first discovered by Vivian Jones of Delta, Colorado, in the middle Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating between 153 to 145 million years ago. It is among the longest dinosaurs ever discovered, with the three known specimens reaching 33–40 meters (108–131 ft) in length, with the largest individual possibly exceeding 40 meters (130 ft) in size. Mass estimates for the WDC and BYU specimens tend to be around 35–44 metric tons in body mass. A potential second species, S. lourinhanensis (Dinheirosaurus), is known from Portugal and has been dated to a similar time.

<span class="mw-page-title-main">Sauropoda</span> Extinct clade of saurischian dinosaurs

Sauropoda, whose members are known as sauropods, is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads, and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Apatosaurus, Argentinosaurus, Alamosaurus, Brachiosaurus, Camarasaurus, Diplodocus, and Mamenchisaurus.

<i>Camarasaurus</i> Camarasaurid sauropod dinosaur genus from Late Jurassic Period

Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs and is the most common North American sauropod fossil. Its fossil remains have been found in the Morrison Formation, dating to the Late Jurassic epoch, between 155 and 145 million years ago.

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

Diplodocids, or members of the family Diplodocidae, are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the Earth, including Diplodocus and Supersaurus, some of which may have reached lengths of up to 42 metres (138 ft).

<i>Cetiosauriscus</i> Genus of reptiles (fossil)

Cetiosauriscus is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian in what is now England. A herbivore, Cetiosauriscus had – by sauropod standards – a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. It has been estimated as about 15 m (49 ft) long and between 4 and 10 t in weight.

<i>Janenschia</i> Extinct genus of dinosaurs from late Jurassic in Lindi Region, Tanzania

Janenschia is a large herbivorous sauropod dinosaur from the Late Jurassic Tendaguru Formation of Lindi Region, Tanzania around 155 million years ago.

<i>Brontosaurus</i> Genus of diplodocid sauropod dinosaur

Brontosaurus is a genus of herbivorous sauropod dinosaur that lived in present-day United States during the Late Jurassic period. It was described by American paleontologist Othniel Charles Marsh in 1879, the type species being dubbed B. excelsus, based on a partial skeleton lacking a skull found in Como Bluff, Wyoming. In subsequent years, two more species of Brontosaurus were named: B. parvus in 1902 and B. yahnahpin in 1994. Brontosaurus lived about 156 to 146 million years ago (mya) during the Kimmeridgian and Tithonian ages in the Morrison Formation of what is now Utah and Wyoming. For decades, the animal was thought to have been a taxonomic synonym of its close relative Apatosaurus, but a 2015 study by Emmanuel Tschopp and colleagues found it to be distinct. It has seen widespread representation in popular culture, being the archetypal "long-necked" dinosaur in general media.

<span class="mw-page-title-main">Diplodocoidea</span> Extinct superfamily of dinosaurs

Diplodocoidea is a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like Supersaurus, Diplodocus, Apatosaurus, and Amphicoelias. Most had very long necks and long, whip-like tails; however, one family are the only known sauropods to have re-evolved a short neck, presumably an adaptation for feeding low to the ground. This adaptation was taken to the extreme in the highly specialized sauropod Brachytrachelopan. A study of snout shape and dental microwear in diplodocoids showed that the square snouts, large proportion of pits, and fine subparallel scratches in Apatosaurus, Diplodocus, Nigersaurus, and Rebbachisaurus suggest ground-height nonselective browsing; the narrow snouts of Dicraeosaurus, Suuwassea, and Tornieria and the coarse scratches and gouges on the teeth of Dicraeosaurus suggest mid-height selective browsing in those taxa. This taxon is also noteworthy because diplodocoid sauropods had the highest tooth replacement rates of any vertebrates, as exemplified by Nigersaurus, which had new teeth erupting every 30 days.

<i>Tornieria</i> Extinct genus of dinosaur

Tornieria is a genus of diplodocid sauropod dinosaur from the Late Jurassic in Lindi Region of Tanzania. It has a convoluted taxonomic history.

<i>Dinheirosaurus</i> Genus of reptiles (fossil)

Dinheirosaurus is a genus of diplodocid sauropod dinosaur that is known from fossils uncovered in modern-day Portugal. It may represent a species of Supersaurus. The only species is Dinheirosaurus lourinhanensis, first described by José Bonaparte and Octávio Mateus in 1999 for vertebrae and some other material from the Lourinhã Formation. Although the precise age of the formation is not known, it can be dated around the early Tithonian of the Late Jurassic.

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

Australodocus is a genus of sauropod dinosaur that lived during the Late Jurassic period, around 150 million years ago, in what is now Lindi Region, Tanzania. Though initially considered a diplodocid, recent analyses suggest it may instead be a titanosauriform.

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

Apatosaurinae is a subfamily of diplodocid sauropods, an extinct group of large, quadrupedal dinosaurs, the other subfamily in Diplodocidae being Diplodocinae. Apatosaurines are distinguished by their more robust, stocky builds and shorter necks proportionally to the rest of their bodies. Several fairly complete specimens are known, giving a comprehensive view of apatosaurine anatomy.

<i>Camarasaurus lentus</i> Species of sauropod

Camarasaurus lentus is an extinct species of sauropod dinosaur that lived during the Jurassic period in what is now the western United States. It is one of the four valid species of the well-known genus Camarasaurus. C. lentus fossils have been found in Wyoming, Colorado, and Utah. It is the species of Camarasaurus found in Dinosaur National Monument and the middle layers of the Morrison Formation. Camarasaurus lentus is among the best-known sauropod species, with many specimens known. A juvenile specimen of C. lentus, CM 11338, is the most complete sauropod fossil ever discovered.

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

Amphicoelias is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian of what is now Colorado, United States. Amphicoelias was moderately sized at about 18 metres (59 ft) in length and 15 metric tons in body mass, shorter than its close relative Diplodocus. Its hindlimbs were very long and thin, and its forelimbs were proportionally longer than in relatives.

<i>Diplodocus</i> Genus of diplodocid sauropod dinosaurs (fossil)

Diplodocus is an extinct genus of diplodocid sauropod dinosaurs known from the Late Jurassic of North America. The first fossils of Diplodocus were discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek διπλός (diplos) "double" and δοκός (dokos) "beam", in reference to the double-beamed chevron bones located in the underside of the tail, which were then considered unique.

<i>Brachiosaurus</i> Sauropod dinosaur genus from the late Jurassic Period

Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154 to 150 million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Colorado River valley in western Colorado, United States. Riggs named the dinosaur Brachiosaurus altithorax; the generic name is Greek for "arm lizard", in reference to its proportionately long arms, and the specific name means "deep chest". Brachiosaurus is estimated to have been between 18 and 22 meters long; body mass estimates of the subadult holotype specimen range from 28.3 to 46.9 metric tons. It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in a steeply inclined trunk, and a proportionally shorter tail.

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

Kaatedocus is a genus of flagellicaudatan sauropod known from the middle Late Jurassic of northern Wyoming, United States. It is known from well-preserved skull and cervical vertebrae which were collected in the lower part of the Morrison Formation. The type and only species is Kaatedocus siberi, described in 2012 by Emanuel Tschopp and Octávio Mateus.

<i>Ardetosaurus</i> Genus of diplodocid sauropod dinosaurs

Ardetosaurus is an extinct genus of diplodocid sauropod dinosaurs from the Late Jurassic (Kimmeridgian) Morrison Formation of northern Wyoming, United States. The genus contains a single species, Ardetosaurus viator. It was first described in 2024 on the basis of a partial articulated skeleton, including vertebrae from the neck, back, and tail, hip bones, and part of the left hindlimb. The genus is a member of the Diplodocinae, a subfamily of large long-necked dinosaurs with whiplike tails. Ardetosaurus represents one of many distinct sauropod taxa that coexisted in this formation.

References

  1. ↑ Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327-329.
  2. ↑ Seebacher, Frank. (2001). "A new method to calculate allometric length-mass relationships of dinosaurs". Journal of Vertebrate Paleontology. 21 (1): 51–60. CiteSeerX   10.1.1.462.255 . doi:10.1671/0272-4634(2001)021[0051:ANMTCA]2.0.CO;2. S2CID   53446536.
  3. ↑ Henderson, Donald (2013). "Sauropod Necks: Are They Really for Heat Loss?". PLOS ONE. 8 (10): e77108. Bibcode:2013PLoSO...877108H. doi: 10.1371/journal.pone.0077108 . PMC   3812985 . PMID   24204747.
  4. ↑ Paul, G.S., 2016, The Princeton Field Guide to Dinosaurs 2nd edition, Princeton University Press p. 213
  5. 1 2 3 4 5 Lovelace, David M.; Hartman, Scott A.; Wahl, William R. (2007). "Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny" (PDF). Arquivos do Museu Nacional, Rio de Janeiro. 65 (4): 527–544. Archived from the original (PDF) on October 6, 2011. Retrieved November 11, 2010.
  6. ↑ "The size of the BYU 9024 animal". svpow.com. June 16, 2019. Archived from the original on April 16, 2022.
  7. ↑ Molina-Perez & Larramendi (2020). Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs. New Jersey: Princeton University Press. p. 36. ISBN   9780691190693.
  8. ↑ Curtice, Brian (November 1–5, 2021). "New Dry Mesa Dinosaur Quarry Supersaurus vivianae (Jensen 1985) axial elements provide additional insight into its phylogenetic relationships and size, suggesting an animal that exceeded 39 meters in length" (PDF). The Society of Vertebrate Paleontology Virtual Meeting conference Program. p. 92. Archived (PDF) from the original on October 8, 2022.
  9. ↑ "How big did Barosaurus get?". August 30, 2016.
  10. ↑ "How big did Barosaurus get?" (PDF). 2016.
  11. ↑ "Supersaurus, Ultrasaurus and Dystylosaurus in 2019, part 2: what we found in Utah". svpow.com. June 15, 2019.
  12. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 McIntosh, John S. (2005). "The genus Barosaurus Marsh (Sauropoda, Diplodocidae)". In Tidwell, Virginia; Carpenter, Ken (eds.). Thunder-lizards: The Sauropod Dinosaurs. Bloomington: Indiana University Press. pp. 38–77. ISBN   978-0-253-34542-4.
  13. 1 2 3 4 5 6 7 8 9 Upchurch, Paul; Barrett, Paul M.; Dodson, Peter (2004). "Sauropoda". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 259–322. ISBN   978-0-520-24209-8.
  14. 1 2 Foster, John R. (1996). "Sauropod dinosaurs of the Morrison Formation (Upper Jurassic), Black Hills, South Dakota and Wyoming". Contributions to Geology, University of Wyoming. 31 (1): 1–25. Archived from the original on June 21, 2010.
  15. 1 2 3 Tschopp, E.; Mateus, O. V.; Benson, R. B. J. (2015). "A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda)". PeerJ. 3: e857. doi: 10.7717/peerj.857 . PMC   4393826 . PMID   25870766.
  16. ↑ Wilson, Jeffrey A. (2002). "Sauropod dinosaur phylogeny: critique and cladistic analysis". Zoological Journal of the Linnean Society. 136 (2): 215–275. doi: 10.1046/j.1096-3642.2002.00029.x . hdl: 2027.42/73066 .
  17. ↑ Lucas, Spencer G.; Spielmann, Justin A.; Rinehart, Larry A.; Heckert, Andrew B.; Herne, Matthew C.; Hunt, Adrian P.; Foster, John R.; Sullivan, Robert M. (2006). "Taxonomic status of Seismosaurus hallorum, a Late Jurassic sauropod dinosaur from New Mexico". In Foster, John R.; Lucas, Spencer G. (eds.). Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin36: 149-161.
  18. 1 2 3 Remes, Kristian (2006). "Revision of the sauropod genus Tornieria africana (Fraas) and its relevance for sauropod paleobiogeography". Journal of Vertebrate Paleontology. 26 (3): 651–669. doi:10.1671/0272-4634(2006)26[651:ROTTSD]2.0.CO;2. S2CID   86119682.
  19. ↑ Remes, Kristian (2007). "A second Gondwanan diplodocid dinosaur from the Upper Jurassic Tendaguru Beds of Tanzania, East Africa" (PDF). Palaeontology. 50 (3): 653–667. Bibcode:2007Palgy..50..653R. doi:10.1111/j.1475-4983.2007.00652.x. S2CID   129739733.
  20. ↑ Harris, Jerald D. (2006). "The significance of Suuwassea emilieae (Dinosauria: Sauropoda) for flagellicaudatan intrarelationships and evolution". Journal of Systematic Palaeontology. 4 (2): 185–198. Bibcode:2006JSPal...4..185H. doi:10.1017/S1477201906001805. S2CID   9646734.
  21. ↑ Marsh, Othniel C. (1890). "Description of new dinosaurian reptiles". American Journal of Science. 3 (39): 81–86. Bibcode:1890AmJS...39...81M. doi:10.2475/ajs.s3-39.229.81. S2CID   131403178.
  22. ↑ Marsh, O.C. (1896). "The dinosaurs of North America". United States Geological Survey, 16th Annual Report, 1894-95. 55: 133–244.
  23. ↑ Marsh, Othniel C. (1898). "On the families of sauropodous Dinosauria". American Journal of Science. 4 (6): 487–488. Bibcode:1899GeoM....6..157M. doi:10.1017/S0016756800142980. S2CID   128770034.
  24. ↑ Marsh, Othniel C. (1899). "Footprints of Jurassic dinosaurs". American Journal of Science. 4 (7): 227–232. Bibcode:1899AmJS....7..227M. doi:10.2475/ajs.s4-7.39.227.
  25. 1 2 Lull, Richard S. (1919). "The sauropod dinosaur Barosaurus Marsh: redescription of the type specimens in the Peabody Museum, Yale University". Memoirs of the Connecticut Academy of Arts and Sciences. 6: 1–42.
  26. ↑ Naish, Darren (February 10, 2017). "Palaeoart Memes and the Unspoken Status Quo in Palaeontological Popularization". Scientific American. Retrieved April 25, 2020.
  27. ↑ Witton, Mark; Naish, Darren; Conway, John (September 2014). "State of the Palaeoart". Palaeontologia Electronica (17.3.5E). doi: 10.26879/145 .
  28. ↑ "Massive Barosaurus skeleton discovered at the ROM" (Press release). Royal Ontario Museum. November 13, 2007. Retrieved February 25, 2009.
  29. 1 2 Royal Ontario Museum. ROM Channel: Constructing the Barosaurus. Added 2012-08-28. Accessed 2012-12-11.
  30. 1 2 National Geographic, Museum Secrets, Episode 3: Royal Ontario Museum, Segment "Lost Dinosaur" Archived July 30, 2021, at the Wayback Machine . Broadcast December 10, 2012.
  31. 1 2 3 National Geographic, Museum Secrets, Episode 3: Royal Ontario Museum, Segment "Lost Dinosaur". Video clips. Archived July 30, 2021, at the Wayback Machine . Broadcast December 10, 2012.
  32. ↑ Anthony Reinhardt. A monster task - putting Gordo together, The Globe and Mail , November 29, 2007.
  33. ↑ Zain Ahmed. Gordo the Barosaurus. Atlas Obscura. March 15, 2021.
  34. ↑ Fraas, Eberhard (1908). "Ostafrikanische Dinosaurier". Palaeontographica. 55: 105–144.
  35. ↑ Seeley, Harry G. (1869). Index to the fossil remains of Aves, Ornithosauria and Reptilia, from the Secondary system of strata arranged in the Woodwardian Museum of the University of Cambridge. Cambridge: Deighton, Bell and Co. pp. 143pp.
  36. ↑ Sternfeld, Richard (1911). "Zur Nomenklatur der Gattung Gigantosaurus Fraas". Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin. 1911: 398.
  37. ↑ Janensch, Werner (1922). "Das Handskelett von Gigantosaurus robustus und Brachiosaurus brancai aus den Tendaguru-Schichten Deutsch-Ostafrikas". Centralblatt für Mineralogie, Geologie und Paläontologie. 1922: 464–480.
  38. ↑ Wild, Rupert (1991). "Janenschia n. g. robusta (E. Fraas 1908) pro Tornieria robusta (E. Fraas 1908) (Reptilia, Saurischia, Sauropodomorpha)". Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie). 173: 1–4.
  39. ↑ Raath, M.A.; McIntosh, J.S. (1987). "Sauropod dinosaurs from the central Zambezi Valley, Zimbabwe, and the age of the Kadzi Formation". South African Journal of Geology . 90 (2): 107–119. ISSN   1012-0750.
  40. ↑ Mark B. Goodwin; Randall B. Irmis; Gregory P. Wilson; David G. DeMar Jr.; Keegan Melstrom; Cornelia Rasmussen; Balemwal Atnafu; Tadesse Alemu; Million Alemayehu; Samuel G. Chernet (2019). "The first confirmed sauropod dinosaur from Ethiopia discovered in the Upper Jurassic Mugher Mudstone". Journal of African Earth Sciences. 159: Article 103571. Bibcode:2019JAfES.15903571G. doi: 10.1016/j.jafrearsci.2019.103571 .
  41. ↑ Taylor, Michael P; Wedel, Mathew J (2013). "The neck of Barosaurus was not only longer but also wider than those of Diplodocus and other diplodocines". PeerJ Preprints. 1: e67v1. doi: 10.7287/peerj.preprints.67v1 .
  42. ↑ Martin, John. 1987. Mobility and feeding of Cetiosaurus (Saurischia, Sauropoda) – why the long neck? pp. 154–159 in P. J. Currie and E. H. Koster (eds), Fourth Symposium on Mesozoic Terrestrial Ecosystems, Short Papers. Boxtree Books, Drumheller (Alberta). 239 pages.
  43. 1 2 3 4 Turner, Christine E.; Peterson, Fred (2004). "Reconstruction of the Upper Jurassic Morrison Formation extinct ecosystem—a synthesis". Reconstruction of the Extinct Ecosystem of the Upper Jurassic Morrison Formation (PDF). Sedimentary Geology167 (3-4): 309-355. Vol. 167. pp. 309–355. Bibcode:2004SedG..167..309T. doi:10.1016/j.sedgeo.2004.01.009.
  44. ↑ Kowallis, Bart J.; Christiansen, Eric H.; Deino, Alan L.; Peterson, Fred; Turner, Christine E.; Kunk, Michael J.; Obradovich, John D. (1998). "The age of the Morrison Formation" (PDF). In Carpenter, Ken; Chure, Daniel J.; Kirkland, James I. (eds.). The Upper Jurassic Morrison Formation: An Interdisciplinary Study. Modern Geology22 (1-4): 235-260. Archived from the original (PDF) on August 24, 2007. Retrieved May 10, 2009.
  45. ↑ Moore, George T.; Hayashida, Darryl N.; Ross, Charles A.; Jacobson, Stephen R. (1992). "Paleoclimate of the Kimmeridgian/Tithonian (Late Jurassic) world: I. Results using a general circulation model". Palaeogeography, Palaeoclimatology, Palaeoecology. 93 (3–4): 113–150. Bibcode:1992PPP....93..113M. doi:10.1016/0031-0182(92)90186-9.
  46. ↑ Ekart, Douglas D.; Cerling, Thure E.; Montanez, Isabel P.; Tabor, Neil J. (1999). "A 400 million year carbon isotope record of pedogenic carbonate; implications for paleoatmospheric carbon dioxide" (PDF). American Journal of Science. 299 (10): 805–827. Bibcode:1999AmJS..299..805E. doi:10.2475/ajs.299.10.805.
  47. ↑ Demko, Timothy M.; Parrish, Judith T. (1998). "Paleoclimatic setting of the Upper Jurassic Morrison Formation". In Carpenter, Ken; Chure, Daniel J.; Kirkland, James I. (eds.). The Upper Jurassic Morrison Formation: An Interdisciplinary Study. Modern Geology22 (1-4): 283-296.
  48. ↑ Engelmann, George F.; Chure, Daniel J.; Fiorillo, Anthony R. (2004). "The implications of a dry climate for the paleoecology of the fauna of the Upper Jurassic Morrison Formation". Reconstruction of the Extinct Ecosystem of the Upper Jurassic Morrison Formation (PDF). Sedimentary Geology167 (3-4): 297-308. Vol. 167. pp. 297–308. doi:10.1016/j.sedgeo.2004.01.008.
  49. ↑ Foster, John R. (2007). Jurassic West: The Dinosaurs of the Morrison Formation and Their World (Appendix). Indiana University Press. pp. 327–329. ISBN   978-0253348708.
  50. ↑ Foster, John R. (2003). Paleoecological Analysis of the Vertebrate Fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain Region, U.S.A. New Mexico Museum of Natural History and Science Bulletin, 23. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. p. 29.
  51. ↑ Carpenter, Kenneth (2006). "Biggest of the big: a critical re-evaluation of the mega-sauropod Amphicoelias fragillimus". In Foster, John R.; Lucas, Spencer G. (eds.). Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin, 36. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 131–138.

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