Eiectus

Last updated

Eiectus
Temporal range: Early Cretaceous, Albian
Kronosaurus queenslandicus.jpg
Specimen MCZ 1285, which may have been reconstructed with too many vertebrae
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Sauropsida
Superorder:
Sauropterygia
Order:
† Plesiosauria
Suborder:
† Pliosauroidea
Family:
† Pliosauridae
Genus:
†Eiectus

Noè & Gómez-Pérez, 2021
Binomial name
†Eiectus longmani
Noè & Gómez-Pérez, 2021
Synonyms

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]

Contents

History

Initial discoveries

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]

MCZ 1285: the Harvard specimen

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]

Scale diagram, showing the size of the restored Harvard Eiectus skeleton along with a more accurate estimate Kronosaurus Scale V2.svg
Scale diagram, showing the size of the restored Harvard Eiectus skeleton along with a more accurate estimate

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]

2021 revision of Kronosaurus

Life restoration based on the Harvard specimen Kronosaurus queenslandicus SW.png
Life restoration based on the Harvard specimen

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]

Related Research Articles

<span class="mw-page-title-main">Alfred Romer</span> American paleontologist

Alfred Sherwood Romer was an American paleontologist and biologist and a specialist in vertebrate evolution.

<i>Kronosaurus</i> Pliosaur genus from the Early Cretaceous period

Kronosaurus is an extinct genus of short-necked pliosaurs that lived during the Early Cretaceous period in what is now Australia. It is a monotypic genus with one species K. queenslandicus, described in 1924 from the Toolebuc Formation in Queensland, Australia. With traditionally attributed fossils indicating a total length of up to 10 meters (33 ft), Kronosaurus may have been among the largest pliosaurs.

<span class="mw-page-title-main">Pliosauroidea</span> Extinct clade of reptiles

Pliosauroidea is an extinct clade of plesiosaurs, known from the earliest Jurassic to early Late Cretaceous. They are best known for the subclade Thalassophonea, which contained crocodile-like short-necked forms with large heads and massive toothed jaws, commonly known as pliosaurs. More primitive non-thalassophonean pliosauroids resembled plesiosaurs in possessing relatively long necks and smaller heads. They originally included only members of the family Pliosauridae, of the order Plesiosauria, but several other genera and families are now also included, the number and details of which vary according to the classification used.

Liopleurodon is an extinct genus of large, carnivorous marine reptile belonging to the Thalassophonea, a clade of short-necked pliosaurid plesiosaurs. Liopleurodon lived from the Callovian Stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic Period. It was the apex predator of the Middle to Late Jurassic seas that covered Europe. The largest species, L. ferox, is estimated to have grown up to 6.6 metres (22 ft) in length based on the largest known skull.

<i>Rhomaleosaurus</i> Genus of rhomaleosaurid plesiosaur from the Early Jurassic period

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, with the type species R. cramptoni measuring 6.7–7 metres (22–23 ft) long and weighing 2.1 metric tons. Like other pliosaurs, Rhomaleosaurus fed on ichthyosaurs, ammonites and other plesiosaurs.

<i>Umoonasaurus</i> Extinct species of reptile

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.

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

Pliosaurus is an extinct genus of thalassophonean pliosaurid known from the Kimmeridgian and Tithonian stages of Europe and South America. Their diet would have included fish, cephalopods, and marine reptiles. This genus has contained many species in the past but recent reviews found only six to be valid, while the validity of two additional species awaits a petition to the International Code of Zoological Nomenclature. Currently, P. brachyspondylus and P. macromerus are considered dubious, while P. portentificus is considered undiagnostic. Most European species of Pliosaurus measured around 8 metres (26 ft) long and weighed about 5 metric tons, but P. rossicus and P. funkei would have been one of the largest plesiosaurs of all time, exceeding 10 metres (33 ft) in length. Species of this genus are differentiated from other pliosaurids based on seven autapomorphies, including teeth that are triangular in cross section.

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

Brachauchenius is an extinct genus of pliosaurid that lived in North America and Morocco during the Late Cretaceous.

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

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).

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

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.

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

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.

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

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 on smaller-sized prey.

<span class="mw-page-title-main">Plesiosaur size</span>

Plesiosaurs are a clade of extinct marine reptiles.

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

Atychodracon is an extinct genus of rhomaleosaurid plesiosaurian known from the Late Triassic - Early Jurassic boundary of England. It contains a single species, Atychodracon megacephalus, named in 1846 originally as a species of Plesiosaurus. The holotype of "P." megacephalus was destroyed during a World War II air raid in 1940 and was later replaced with a neotype. The species had a very unstable taxonomic history, being referred to four different genera by various authors until a new genus name was created for it in 2015. Apart from the destroyed holotype and its three partial casts, a neotype and two additional individuals are currently referred to Atychodracon megacephalus, making it a relatively well represented rhomaleosaurid.

Luskhan is an extinct genus of brachauchenine pliosaur from the Cretaceous of Russia. The type and only species is Luskhan itilensis, named by Valentin Fischer and colleagues in 2017 from a well-preserved and nearly complete skeleton. As an early-diverging brachauchenine, Luskhan consequently exhibits an intermediate combination of traits seen in more basal and more derived pliosaurs. However, Luskhan departs significantly from other pliosaurs in that it exhibits a lack of adaptations in its skull to feeding on large prey; its slender snout, small teeth, and short tooth rows instead indicate a skull adapted for feeding on small, soft prey. With these features, it is the pliosaur that approaches closest to the distantly-related piscivorous polycotylids, having convergently evolved these traits more than 10 million years apart.

<span class="mw-page-title-main">William E. Schevill</span> American paleontologist

William Edward "Bill" Schevill was an American paleontologist famous for his part in dynamiting out the nodules of the most complete skeleton of the short-necked pliosaur Kronosaurus queenslandicus discovered in Hughenden in Queensland, Australia, in 1932. He later became known as an authority on the sounds of whales. Schevill had the title of scientist emeritus at the Woods Hole Oceanographic Institution, where he had begun working in 1943, technically retiring in 1985.

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

Lagenanectes is a genus of elasmosaurid plesiosaur from the Lower Cretaceous, found in Lower Saxony, Germany. The only species, Lagenanectes richterae, was first described in 2017, and is regarded as one of the best-preserved plesiosaur fossils from this geological age in Europe. Lagenanectes is one of the earliest elasmosaurids. The holotype is an incomplete skeleton, comprising large parts of the skull, some neck and tail vertebrae as well as ribs and part of the limbs. A length of about 8 meters has been estimated.

<span class="mw-page-title-main">Harvard Australian Expedition (1931–1932)</span>

The Harvard Australian Expedition of 1931–1932 was a six-man venture sent by then Harvard Museum of Comparative Zoology (MCZ) director Thomas Barbour to Australia for the dual purpose of procuring specimens and studying native (living) wildlife in its natural habitat. The Expedition leader was Harvard Professor William Morton Wheeler, with the others being Dr. Philip Jackson Darlington, Jr., Dr. Glover Morrill Allen and his student Ralph Nicholson Ellis, medical officer Dr. Ira M. Dixon, and William E. Schevill . The Expedition was a success, with 341 mammal, 545 amphibian, and thousands of insect specimens returning to the United States., yet its most famous legacy and find was the accidental discovery of the world's most complete skeleton of the short-necked pliosaur Kronosaurus queenslandicus.

The Bulldog Shale is a formation of Early Cretaceous age that forms part of the Marree Subgroup of the Rolling Downs Group, located in the Eromanga Basin of South Australia, Queensland and New South Wales.

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

Monquirasaurus is an extinct genus of giant short-necked pliosaurs who lived during the Early Cretaceous (Aptian) in what is now Colombia. One species is known, M. boyacensis, described in 2021 from an almost complete fossil skeleton, discovered in 1977 in the town of Villa de Leyva, located in Boyacá. Published descriptions of the holotype specimen estimate that it should reach a total size approaching 8 m (26 ft) in length, making Monquirasaurus a large representative of the pliosaurids.

References

  1. ↑ Hampe O. (1992). Ein großwüchsiger Pliosauride (Reptilia: Plesiosauria) aus der Unterkreide (oberes Aptium) von Kolumbien. Courier Forschungsinstitut Senckenberg145: 1–32.
  2. ↑ Kear BP. (2003). Cretaceous marine reptiles of Australia: a review of taxonomy and distribution. Cretaceous Research 24: 277–303.
  3. 1 2 3 4 Noè, L.F.; Gómez-Pérez, M. (2021). "Giant pliosaurids (Sauropterygia; Plesiosauria) from the Lower Cretaceous peri-Gondwanan seas of Colombia and Australia". Cretaceous Research. 132: 105122. doi:10.1016/j.cretres.2021.105122.
  4. 1 2 3 4 Mather, Patricia, with Agnew, N.H. et al. The History of the Queensland Museum, 1862–1986 Retrieved from archive.org
  5. 1 2 Gardiner, J. Stanley (September 1931). "The Harvard Museum Expedition to Australia". Nature. 128 (3228): 457–458. Bibcode:1931Natur.128..457G. doi:10.1038/128457c0. S2CID   29715877.
  6. 1 2 Capinera, John L. (2008). "Darlington, Jr., Philip J". Encyclopedia of Entomologists. pp. 1153–1154. ISBN   9781402062421.
  7. ↑ Hangay, George; Keyzer, Roger de. A Guide to Stag Beetles of Australia. Csiro Publishing. ISBN   978-1-4863-0209-3.
  8. ↑ Ralph Ellis archives, 1898–1972 – http://etext.ku.edu/view?docId=ksrlead/ksrl.sc.ellisralpharchives.xml Archived 2019-12-27 at the Wayback Machine
  9. 1 2 3 4 5 About the Exhibits by Elizabeth Hall and Max Hall (Museum of Comparative Zoology "Agazziz Museum" Harvard University. Third Edition, Copyright 1964, 1975, 1985, by the President and Fellows of Harvard College
  10. ↑ Annual report of the director of the Museum of Comparative Zoology at Harvard College, to the president of Harvard College for 1932–1933. Cambridge, U.S.A.: Printed for the Museum p.54-58 [BHL – https://www.biodiversitylibrary.org/page/41109461#page/58/mode/1up]
  11. ↑ "News-Press from Fort Myers, Florida". Newspapers.com. 1989-01-26. Retrieved 2023-09-05.
  12. ↑ "Trove". trove.nla.gov.au. Retrieved 2023-09-05.
  13. 1 2 3 Meyers, Troy. Kronosaurus Chronicles. Australian Age of Dinosaurs, Issue 3, 2005. Retrieved from australianageofdinosaurs.com [ permanent dead link ]
  14. ↑ "Zoology Museum to Exhibit Largest Sea-Reptile Fossil | News | The Harvard Crimson". www.thecrimson.com. Retrieved 2023-09-05.
  15. ↑ Rolfe, WD Ian. "William Edward Schevill: palaeontologist, librarian, cetacean biologist." Archives of Natural History 39.1 (2012): 162–164. – https://www.euppublishing.com/doi/pdfplus/10.3366/anh.2012.0069
  16. ↑ 1930s: The One That Got Away – https://australianmuseum.net.au/blogpost/museullaneous/1930s-the-one-that-got-away
  17. 1 2 3 The Rarest of the Rare: Stories Behind the Treasures at the Harvard Museum of Natural History (Hardcover) – 26 October 2004
  18. ↑ Romer, A. S. and A. D. Lewis. 1959. A mounted skeleton of the giant plesiosaur Kronosaurus. Breviora 112:1–15.
  19. ↑ Welles, S. P., (1962), A new Species of Elasmosaur from the Aptian of Colombia and a review of the Cretaceous Plesiosaurs. University of California Publications Bulletin Department of Geological Sciences 44: 1-89
  20. ↑ Molnar, R.E., (1982a). Australian Mesozoic reptiles. In: Rich, P.V., Thompson, E.M. (Eds.). Vertebrate palaeontology of Australasia. Monash University, Clayton, pp. 170–220.
  21. ↑ Molnar, R.E., (1991). Fossil reptiles in Australia. In: Vickers-Rich, P., Monaghan, J.M., Baird, R.F. et al., (Eds.). Vertebrate palaeontology of Australasia. Pioneer Design Studio, Monash University, Melbourne, pp. 605–702.
  22. ↑ Thulborn, T., Turner, S., (1993). An elasmosaur bitten by a pliosaur. Modern Geology 18, 489–501.
  23. ↑ Valentin Fischer; Roger B. J. Benson; Nikolay G. Zverkov; Maxim S. Arkhangelsky; Ilya M. Stenshin; Gleb N. Uspensky; Natalya E. Prilepskaya (2023). "Anatomy and relationships of the bizarre Early Cretaceous pliosaurid Luskhan itilensis". Zoological Journal of the Linnean Society . 198 (1): 220–256. doi:10.1093/zoolinnean/zlac108. S2CID   257573659.
  24. ↑ https://www.tandfonline.com/doi/full/10.1080/03115518.2023.2228367?scroll=top&needAccess=true&role=tab
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.