Eiectus Temporal range: Early Cretaceous, | |
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Specimen MCZ 1285, which may have been reconstructed with too many vertebrae | |
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Genus: | †Eiectus Noè & Gómez-Pérez, 2021 |
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†Eiectus longmani Noè & Gómez-Pérez, 2021 | |
Eiectus is a potentially valid genus of extinct short-necked pliosaur that lived in the Early Cretaceous period. [1] [2] Fossil material has been recovered from the Wallumbilla Formation (Aptian) of Queensland was initially classified under the related genus Kronosaurus until 2021. [3]
A partial skull previously assigned to Kronosaurus queenslandicus that was discovered in 1929 in the same place as the holotype of K. queenslandicus probably belonged to Eiectus, [3] and another skull discovered in 1935 near Telemon Station in Hughenden, Queensland and prepared in May 1936 may have also belonged to Eiectus, [4] along with all other Albian remains previously referred to K. queenslandicus. [3]
In 1931 the Harvard Museum of Comparative Zoology (MCZ) sent an expedition to Australia for the dual purpose of procuring specimens – the museum being "weak in Australian animals and...desires[ing] to complete its series" – and to engage in "the study of the animals of the region when alive." [5] The Harvard Australian Expedition (1931–1932), as it became known, was a six-man venture led by Harvard Professor William Morton Wheeler, with the others being Dr. P. Jackson Darlington Jr. (a renowned coleopterist), [6] [7] Dr. Glover Morrill Allen and his student Ralph Nicholson Ellis, [8] medical officer Dr. Ira M. Dixon, and William E. Schevill (a graduate-student in his twenties and Associate Curator of Invertebrate Palaeontology). [9] [5] [10] MCZ director Thomas Barbour said at the time "We shall hope for specimens' of the kangaroo, the wombat, the Tasmanian devil and Tasmanian wolf," and the mission was a success with over 300 mammal and thousands of insect specimens returning to the United States. [6] [9] Yet Mr. Schevill, the team's fossil enthusiast, remained in Australia after the others had departed and, in the winter of 1932, was told by the rancher R.W.H. Thomas of rocks with something "odd" poking out of them on his property near Hughenden. [4] [11] [9] [12] The rocks were limestone nodules containing the most complete skeleton of Kronosaurus ever discovered. [4] [13] [14] After dynamiting the nodules out of the ground (and into smaller pieces weighing approximately four tons [15] [16] ) with the aid of a British migrant trained in the use of explosives, [17] William Schevill had the fossils shipped back to Harvard for examination and preparation. The skull—which matched the holotype jaw fragment of K. queenslandicus—was prepared right away, but time and budget constraints put off restoration of the nearly complete skeleton – most of the bones of which remained unexcavated within the limestone blocks – for 20 years. [13]
This interim ended when they came to the attention of Godfrey Lowell Cabot – Boston industrialist, philanthropist, and founder of the Cabot Corporation – "who was then in his nineties" and "had been interested in sea serpents since childhood." [9] Having formerly questioned MCZ director Alfred Romer about the existence and reports of sea serpents, it thus occurred to Dr. Romer to tell Mr. Cabot about the skeleton in the museum closet. Godfrey Cabot thus asked how much a restoration would cost and "Romer, pulling a figure out of the musty air, replied, 'Oh, about $10,000.'" Romer may not have been serious but the philanthropist clearly was because the check for said sum came shortly thereafter. [9] [17] Two years – and more than $10,000 – later, following the careful labor of the museum preparators, the restored and mounted skeleton was displayed at Harvard in 1959. [4] [13] However, Dr. Romer and MCZ preparator Arnold Lewis confirmed that same year in the institution's journal Breviora that "erosion had destroyed a fair fraction of this once complete and articulated skeleton...so that approximately a third of the specimen as exhibited is plaster restoration." [18] Furthermore, the original (real) bones are also layered in plaster; a fact that, while keeping the fossils safe, makes it difficult for paleontologists to study it – an issue which factors into the controversial question of the true size of the Kronosaurus queenslandicus. [17]
Welles (1962) suggested that MCZ 1285 should be the neotype of what would later become Eiectus. [19] Molnar (1982a, 1991) suggested that MCZ 1285 may not be conspecific with the holotype of Kronosaurus queenslandicus, [20] [21] but instead believing that it represents a second species or a new genus that differs in having a deeper and more robust skull (followed by Thulborn and Turner, 1993). [22]
In 2021, a revision of K. boyacensis also transferred most of the remains of K. queenslandicus, including the Harvard remains, to a new genus and species, Eiectus longmani. The revision limits the genus Kronosaurus to the holotype mandible, and treats it as a nomen dubium . [3] Fischer et al. (2023) criticized the reassignments even under these circumstances, predicting that they stand contrary to ICZN Articles 75.5 and 75.6 (which codifies preference for neotype designation for previously iconic taxa with non-diagnostic holotypes) and that the aforementioned multiple-species possibility cannot justify a tentative reassignment of all specimens to Eiectus. The authors instead opted to refer to all relevant fossils as Kronosaurus-Eiectus. [23] A 2023 review of Australian fossil tetrapods restricted the name Eiectus to specimens MCZ 1285 and MCZ 1284. [24]
Plesiosauroidea is an extinct clade of carnivorous marine reptiles. They have the snake-like longest neck to body ratio of any reptile. Plesiosauroids are known from the Jurassic and Cretaceous periods. After their discovery, some plesiosauroids were said to have resembled "a snake threaded through the shell of a turtle", although they had no shell.
Elasmosaurus is a genus of plesiosaur that lived in North America during the Campanian stage of the Late Cretaceous period, about 80.5 million years ago. The first specimen was discovered in 1867 near Fort Wallace, Kansas, US, and was sent to the American paleontologist Edward Drinker Cope, who named it E. platyurus in 1868. The generic name means "thin-plate reptile", and the specific name means "flat-tailed". Cope originally reconstructed the skeleton of Elasmosaurus with the skull at the end of the tail, an error which was made light of by the paleontologist Othniel Charles Marsh, and became part of their "Bone Wars" rivalry. Only one incomplete Elasmosaurus skeleton is definitely known, consisting of a fragmentary skull, the spine, and the pectoral and pelvic girdles, and a single species is recognized today; other species are now considered invalid or have been moved to other genera.
Kronosaurus is an extinct genus of large short-necked pliosaur that lived during the Aptian to Albian stages of the Early Cretaceous in what is now Australia. The first known specimen was received in 1899 and consists of a partially preserved mandibular symphysis, which was first thought to come from an ichthyosaur according to Charles De Vis. However, it was 1924 that Albert Heber Longman formally described this specimen as the holotype of an imposing pliosaurid, to which he gave the scientific name K. queenslandicus, which is still the only recognized species nowadays. The genus name, meaning "lizard of Kronos", refers to its large size and possible ferocity reminiscent of the Titan of the Greek mythology, while the species name alludes to Queensland, the Australian state of its discovery. In the early 1930s, the Harvard Museum of Comparative Zoology sent an organized expedition to Australia that recovered two specimens historically attributed to the taxon, including a well known skeleton that is now massively restored in plaster. Several attributed fossils were subsequently discovered, including two large, more or less partials skeletons. As the holotype specimen does not present diagnostics to concretely distinguish Kronosaurus from other pliosaurids, these same two skeletons are proposed as potential neotypes for future redescriptions. Two additional species were proposed, but these are now seen as unlikely or belonging to another genus.
Rhomaleosaurus is an extinct genus of Early Jurassic rhomaleosaurid pliosauroid known from Northamptonshire and from Yorkshire of the United Kingdom. It was first named by Harry Seeley in 1874 and the type species is Rhomaleosaurus cramptoni. It was one of the earliest large marine reptile predators which hunted in the seas of Mesozoic era, measuring about 7 metres (23 ft) long. Like other pliosaurs, Rhomaleosaurus fed on ichthyosaurs, ammonites and other plesiosaurs.
Umoonasaurus is an extinct genus of plesiosaur belonging to the family Leptocleididae. This genus lived approximately 115 million years ago during the Early Cretaceous period, in shallow seas covering parts of what is now Australia. It was a relatively small animal around 2.5 metres (8.2 ft) long. An identifying trait of Umoonasaurus is three crest-ridges on its skull.
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Brachauchenius is an extinct genus of pliosaurs that lived during the Late Cretaceous in what are now North America and North Africa. Only one species is known, B. lucasi, initially described by Samuel Wendell Williston in 1903 from a partial fossil skeleton discovered in a quarry in Kansas, United States. Many other fossil specimens attributed to the species were subsequently discovered, including an individual from Morocco whose presence was made official in 2016. Many contemporary pliosaur specimens were formerly attributed to Brachauchenius, but have since been reidentified as belonging to other genera or are recognized as indeterminate.
Leptocleidus is an extinct genus of plesiosaur, belonging to the family Leptocleididae. It was a small plesiosaur, measuring only up to 3 m (9.8 ft).
Megalneusaurus is an extinct genus of large pliosaurs that lived during the Oxfordian and Kimmeridgian stages of the Late Jurassic in what is now North America. It was provisionally described as a species of Cimoliosaurus by the geologist Wilbur Clinton Knight in 1895, before being given its own genus by the same author in 1898. The only species identified to date is M. rex, known from several specimens identified in the Redwater Shale Member, within the Sundance Formation, Wyoming, United States. A specimen discovered in the Naknek Formation in southern Alaska was referred to the genus in 1994. In Ancient Greek, the generic name literally translates to "large swimming lizard", due to the measurement of the fossils of the holotype specimen.
Hauffiosaurus is an extinct genus of Early Jurassic pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is Hauffiosaurus zanoni. In 2011, two additional species were assigned to this genus: H. longirostris and H. tomistomimus.
This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of plesiosaurs, an order of marine reptiles that flourished during the Mesozoic Era. The first scientifically documented plesiosaur fossils were discovered during the early 19th century by Mary Anning. Plesiosaurs were actually discovered and described before dinosaurs. They were also among the first animals to be featured in artistic reconstructions of the ancient world, and therefore among the earliest prehistoric creatures to attract the attention of the lay public. Plesiosaurs were originally thought to be a kind of primitive transitional form between marine life and terrestrial reptiles. However, now plesiosaurs are recognized as highly derived marine reptiles descended from terrestrial ancestors.
Megacephalosaurus is an extinct genus of short-necked pliosaur that inhabited the Western Interior Seaway of North America about 94 to 93 million years ago during the Turonian stage of the Late Cretaceous, containing the single species M. eulerti. It is named after its large head, which is the largest of any plesiosaur in the continent and measures up to 1.75 meters (5.7 ft) in length. Megacephalosaurus was one of the largest marine reptiles of its time with an estimated length of 6–9 meters (20–30 ft). Its long snout and consistently sized teeth suggest that it preferred a diet of smaller-sized prey.
Stenorhynchosaurus is an extinct genus of pliosaurid plesiosaurs which lived in the Early Cretaceous of South America. The type species and only known is Stenorhynchosaurus munozi.
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