Kronosaurus

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Kronosaurus
Temporal range: Aptian-Late Albian
~120–100 Ma
Proposed neotype skull, QM F18827
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: †Sauropterygia
Order: †Plesiosauria
Family: †Pliosauridae
Subfamily: †Brachaucheninae
Genus: †Kronosaurus
Longman, 1924
Type species
†Kronosaurus queenslandicus
Synonyms
  • Eiectus longmani Noè & Gómez-Pérez, 2021

Kronosaurus (/ˌkrɒnoʊˈsɔːrəs/ KRON-oh-SOR-əs; meaning "lizard of Kronos") is an extinct genus of short-necked pliosaurs that lived during the Early Cretaceous period (Aptian to Late Albian) 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.

The status of this genus is contentious due to the fragmentary nature of the holotype, which is a non-diagnostic partial mandibular symphysis. This led to a 2021 study to reduce Kronosaurus to a dubious taxon and reassign all other fossils previously assigned to it, including several partial skeletons, to a new genus. The move was heavily criticized as introducing taxonomic instability by supplanting an iconic name when a preferred solution would have been to petition the ICZN to designate a diagnostic neotype. Although a petition has yet to be submitted, several specimens have already been proposed as neotypes, and subsequent studies have maintained the use of Kronosaurus on this account.

Kronosaurus inhabited the Eromanga Sea, an inland sea that covered parts of central and eastern Australia during the Early Cretaceous and reached rather cold temperatures. It was probably an apex predator that preyed on other marine reptiles. Remains of plesiosaurs and turtles have been found as stomach contents of traditional specimens from the Toolebuc Formation.

Research history[edit]

Initial finds and research[edit]

QM F1609, the holotype mandibular symphysis of K. queenslandicus

In 1899, a partial fossil of a marine reptile was sent on behalf of a certain Andrew Crombie to the Queensland Museum of Brisbane, Australia, and was received by the zoologist Charles De Vis, who was then the director of the museum during that time.[1] No information regarding the origin locality of the fossil is known,[2][1][3] but it seems that it was probably discovered near of Hughenden, Queensland, a town from which Crombie comes.[4][5] Queensland Museum records show that De Vis even sent a letter to Crombie informing him that he had been made aware of the receipt of the material.[6] The fossil in question, cataloged as QM F1609, consists of a partial mandibular symphysis bearing six conical teeth.[4][1] Based on his observations, De Vis considers the fossil to come from a representative of the Enaliosauria, a now obsolete taxon which included plesiosaurs and ichthyosaurs. De Vis initially thought the specimen came from an ichthyosaur, specifically Ichthyosaurus australis,[1] which today seems to be placed in the genus Platypterygius.[7] However, the particular dentition of this specimen quickly makes it change its mind about whether it belongs to this specific genus. The fossil was officially described by De Vis's successor, Albert Heber Longman, in a scientific article published in 1924 by the journal of the Queensland Museum. Longman deduces that the fossil comes from a large pliosaur, to which he gives the genus and species name Kronosaurus queenslandicus.[4][5][1] The generic name comes from Kronos, a Titan from the Greek mythology, and from ancient Ancient Greek σαῦρος (saûros, "lizard"), to literally give "lizard of Kronos". Longman would have created this generic name in reference to the imposing size and possible ferocity of the animal, which could recall the story of Kronos, who is known in Greek mythology for having devoured his own children, notably Zeus.[8][9][1][3][10] The specific epithet queenslandicus is named after the Queensland, the Australian state where the holotype specimen was discovered.[8][10][3]

Saturn Devouring His Son, artist's impression by Francisco de Goya, painted between 1820 and 1823, representing the Titan of the Greek mythology Kronos. Kronosaurus is named in reference to the latter for its large size and its possible ferocity reminiscent of the character[8][9][1][3][10]

In August 1929, fifteen more or less partial fossils[11] are discovered nearly 3.2 km south of Hughenden.[1] These same fossils, all catalogued as QM F2137,[3][12] are identified as coming from the Toolebuc Formation, dating from the Albian stage of the Late Cretaceous, the holotype having very probably also been discovered in this same locality.[13] The majority of the material recovered is then very incomplete, the only two that can be concretely described being proximal parts of propodials (upper limb bones),[3][1] which are analyzed in more detail the following year, and those again by Longman.[11] In 1932, in an effort to make the animal's fossils "attractive", Longman published one of the oldest known reconstructions of Kronosaurus. The illustration was drawn in 1931 by a certain Wilfrid Morden, who was inspired in particular by the anatomical features of Peloneustes to fill in the still unknown parts of the animal.[14]

In May and April 1935, a certain J. Edgar Young, a collector working at the Queensland Museum, collected several fossils from the Toolebuc Formation, more precisely from the Telemon station, about 30 km west of Hughenden.[15] Among all the fossils Young was involved in exhuming are additional remains attributed to Kronosaurus, including the first somewhat more complete cranial parts identified within the genus. In his article published in October 1935, Longman, due to the high number of fossils, suggested that they came from at least two or three individuals. Noting that the fossils were not fully prepared at the time of his description, he describes them preliminary.[16] The most notable specimen, cataloged QM F2446,[17][3][2] consists of a partial middle of the skull which preserves an occipital condyle, the back of the neurocranium, the external nostrils as well as the orbits.[15]

Harvard expedition[edit]

Main article: Harvard Australian Expedition (1931–1932)

In 1931, the Museum of Comparative Zoology sent an expedition to Australia with the dual aim of obtaining specimens of both living and extinct animals,[13] and in particular marsupial mammals.[18] This decision came from the fact that the museum had relatively few Australian animals and therefore wanted to collect more. It was then that the Harvard Australian Expedition began, and was undertaken by a team of six men. The team consisted of coleopterologist P. Jackson Darlington Jr., zoologist Glover Morrill Allen and his student Ralph Nicholson Ellis, chief physician Ira M. Dixon, paleontologist William E. Schevill, and their leader, entomologist William Morton Wheeler.[19][8][18] The following year, in 1932, it was Schevill who acquired the title of expedition leader, making long journeys and recruiting local help when he could. The Queensland Museum was also invited to participate in this expedition, but this was never approved due to lack of funds and/or interest from the state government. However, Longman, who described the first known fossils of Kronosaurus, nevertheless assisted the expedition, storing specimens as they were sent to him, securing collecting permits, and maintaining correspondence with Schevill.[5] Schevill then ventured into the Rolling Downs geological group, north of the town of Richmond, where he collected two large pliosaur specimens.[13] These same specimens are collected from the Doncaster Member of the Wallumbilla Formation, dating back approximately 112 million years.[15] The first specimen he exhumed, cataloged as MCZ 1284 and discovered on a property called Grampian Valley, consisted of a well-preserved piece of the anterior rostrum closely connected to the entire mandibular symphysis, in addition to several other fragmentary pieces.[13][20][21]

MCZ 1285, the Harvard skeleton historically attributed to Kronosaurus, sometimes nicknamed "Plasterosaurus". This specimen would have been reconstructed with too many vertebrae and with wrong cranial proportions

The story regarding the discovery, exhumation and exhibition of the second specimen, cataloged as MCZ 1285, is much more detailed in many historical sources.[20][21][8][5][9][18][13] This specimen was discovered long before the Harvard Expedition was even launched, by a rancher named Ralph William Haslam Thomas,[22] in a locality known as Army Downs.[21][13] The latter had been aware for many years of the presence of “something strange coming out of the ground” in a small horse enclosure.[5][18] These “strange things” were actually a row of vertebrae contained in nodules.[22] Noticing his discovery, Thomas therefore informed the members of the Harvard expedition,[22] and notably Schevill.[5][18][13] The latter then contacts a British migrant trained in the use of explosives, nicknamed "The Maniac" by local residents,[a][5][18][13] in order to extract the specimen of 4.5 metric tons (5.0 short tons) of rock which constitutes its geological matrix.[23] When the specimen was unearthed, its fossils were then sent to the United States in 86 crates weighing a total of 6 metric tons (6.6 short tons).[8][22][18] According to the export permit, the specimen was transported aboard the SS Canadian Constructor around December 1, 1932.[22]

Once arrived at Harvard, the fossils, which represent approximately 60% of the skeleton, took several years to extract from the limestone.[18] The lack of money, manpower and space within the museum is the cause of the long delays, and it will take until 1939 only for the skull to be mounted and exhibited.[8] However, a first scientific description of the skull was made by Theodore E. White in 1935.[20] One year earlier, in 1934, Schevill asked Longman to send a cast of the holotype mandibular symphysis for comparison with the new specimen. It was then Longman's assistant, a certain Tom Marshall, who took it upon himself to make Schevill's request.[5] The researchers then realized that the characters of the holotype (QM F1609) were identical to those of the Harvard specimen (MCZ 1285).[23] Longman, in his letters to Schevill, suggests that he would have enjoyed seeing the specimen during its preparation in the late 1930s, but it never left Australian territory.[5]

The rest of the skeleton was kept in the basement of the museum for more than fifteen years. This interim period ended when the fossils attracted the attention of Godfrey Lowell Cabot, a Boston industrialist, philanthropist and founder of the Cabot Corporation. Cabot's family had a history of sighting large sea snakes in the coastal waters around the town he is from. When questioning the museum's director, Alfred Sherwood Romer, about the existence and reports of sea serpents, it occurred to Romer to tell Cabot about the skeleton kept in the museum's basement.[8][24] So Cabot asks about the cost of a restoration and Romer says about $10,000. Romer may not have been serious, but Cabot clearly was because the check for said sum came shortly after.[8][18] Given that Romer's primary interest was the study of non-mammalian synapsids, it is possible that he had little regard for the skeleton as a subject of scientific study.[25] After two years of careful preparations with chisel and acid by Arnold Lewis and James A. Jensen under Romer's direction, their work ultimately cost slightly more than promised by Cabot's base check.[8][18] The Harvard skeleton was exhibited for the first time on June 10, 1958,[8] and is followed by a detailed scientific description carried out by Romer and Lewis, which was published the following year by the museum journal.[21][24] When the finalization of the specimen was announced in the Australian press, Longman, who is the descriptor of the taxon, was not mentioned. In response, professor and geologist Walter Heywood Bryan sent a message via telegraph informing journalists that it would be regrettable if such an important announcement made no mention of Longman and the interpretation of the initially fragmentary fossil material.[5] At the age of 93, Thomas, the original discoverer of the specimen, was able to see the mounted skeleton of what he considered "his dinosaur", as well as meet the leader of the museum's former expedition, each believing that the other had been dead for a long time.[22]

The arrival of new knowledge in the field of paleontology subsequently calls into question the restoration of the skeleton as proposed by Romer. Indeed, because of many incomplete bones, the latter ordered Lewis and Jensen to add plaster where he deemed it necessary. This latest decision has made it difficult for paleontologists to access real fossils,[18] to the point where some of them use the nickname “Plasterosaurus” to refer to the specimen.[26][27][28][29] In addition, it seems that the skeleton was reconstructed with the wrong proportions. According to Australian paleontologist Colin McHenry, the specimen has 8 extra vertebrae added to the spine[18] and the skull is not supposed to have a bulbous shaped sagittal crest on top.[26] In his thesis revising the genus Kronosaurus published in 2009, McHenry called the Harvard skeleton "a rather disappointing restoration of what must have been an excellent fossil specimen".[25] For this reason, many researchers express their desire to analyze real fossils using CT scans.[28][29]

Later discoveries and genus validity[edit]

Assigned specimen in Kronosaurus Korner museum, Queensland

Given that the holotype specimen of K. queenslandicus (QM F1609) is fragmentary and does not present any unique characteristics that would qualify the genus as distinct from other pliosaurs, the validity of this taxon has therefore been questioned. As early as 1962, Samuel Paul Welles considered Kronosaurus as a nomen vanum and recommended the designation of a neotype specimen from Harvard University which would preserve the genus validity.[30][b] From 1979,[5] a good number of fossils from large pliosaurs are discovered in various localities in Australia, mainly in the geological strata of the Toolebuc Formation, the formation from which the first fossils attributed to the genus were discovered.[32] In other formations, only one additional attributed specimen was discovered in the Doncaster Member of the Wallumbilla Formation,[33] while three specimens, including one attributed to the type species, were discovered in the Allaru Formation.[34][35][36][37] In his 2009 thesis, McHenry describes in detail many fossils attributed to Kronosaurus, including most of the new specimens that he judges to possibly belong to this genus.[38][c] Of the numerous fossil specimens that he analyzed, McHenry proposed that two partial skeletons, cataloged as QM F10113 and QM F18827, which both come from the Toolebuc Formation, could be candidate neotypes, because they present features that seem to fit with the holotype.[39] However, no formal ICZN petition to designate a neotype was submitted. In 2021, Leslie Francis Noè and Marcela Gómez-Pérez published a study that revised most of the specimens historically attributed to Kronosaurus. Both authors limit Kronosaurus only to the holotype and consider it a nomen dubium. The holotype specimen does not possess any features allowing a diagnostic, the other attributed fossils are provisionally moved to a new taxon that the two authors name Eiectus longmani, in homage to Longman, the paleontologist who named the original genus. The Harvard skeleton (MCZ 1285) is also designated a holotype of this same genus.[40]

In 2023, Valentin Fischer and colleagues 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.[41] The same year, Stephen F. Poropat and colleagues maintained K. queenslandicus as a nominally valid taxon that includes all fossils from the Toolebuc and Allaru Formation pending an official ICZN petition, recommending specimen QM F18827 as neotype.[42] The authors also criticize the repurposing of Toolebuc specimens,[29] on the grounds that Noè and Gómez-Pérez presumably ignored the conclusion of McHenry's 2009 thesis that only one species of large pliosaur exists in the formation and that, therefore, all of its specimens can be reliably considered conspecific to the holotype.[43] As for Eiectus, Poropat and colleagues limit it only to MCZ 1285 and the referred specimen MCZ 1284, but their assignment without formal redescription also remains subject to debate, given that the holotype is so massively restored with plaster that all features apparent diagnostics are probably unreliable without comprehensive CT scans.[29]

Species proposed or formerly classified[edit]

Fossil skeleton of a pliosaur kept in a museum
Holotype skeleton of Monquirasaurus, which was formerly classified as K. boyacensis.

Although the only currently recognized species of Kronosaurus is K. queenslandicus, several authors have suggested the existence of additional species within the genus. In 1982 and again in 1991, Molnar expressed doubts as to whether the Harvard skeleton (MCZ 1285) belonged to the species K. queenslandicus, given that it was discovered in a locality distinct from that of the first known specimens, namely in the older Wallumbilla Formation. The author therefore suggests that this specimen would belong to another species of Kronosaurus characterized by a deeper and more robust skull than those coming from the Toolebuc Formation.[17][9][44][25] A study published in 1993 also attributes the specimen under the name Kronosaurus sp., the authors following the same opinion as Molnar.[45] However, as White indicates in his description of the specimen in 1935, much of the skull roof is not preserved and is mostly restored in plaster.[20] In his 2009 thesis, McHenry nevertheless continues to refer the specimen to K. queenslandicus because of its taphonomic distribution and certain traits which may be consistent with other specimens discovered in the Toolebuc Formation.[46] To determine whether this statement is true, only a CT scan could reveal the presence of the true notable differences within this reconstructed plaster specimen.[28][29]

In 1977, an almost complete skeleton of a large pliosaur was discovered by local residents of the town of Villa de Leyva, Colombia. The specimen, nicknamed "El Fósil" and dating from the Upper Aptian of the Paja Formation, was first provisionally referred to the genus Kronosaurus two years later, in 1979.[47] It was in 1992 that the German paleontologist Olivier Hampe established a second species of the genus under the name of K. boyacensis, the specific name referring to Boyacá, the department surrounding the discovery site.[48] However, these descriptions were made from photographs and remote imaging techniques, in particular because access to the specimen was prohibited by the local community. It was therefore in 2021 that Noè and Gómez-Pérez re-described this specimen and discovered that it belonged to a distinct genus, which they named Monquirasaurus, in reference to Monquirá, the administrative division where the specimen was discovered.[40]

Description[edit]

Size[edit]

Size of the largest specimen traditionally attributed to Kronosaurus (MCZ 1285) with a human. The light gray diagram represents the size of the specimen as it is currently mounted at the Museum of Comparative Zoology, while the dark gray one shows it with a more accurate estimate

Kronosaurus has a morphology typical of the pliosaurids of the thalassophonean group, which has a large elongated skull connected to a neck of reduced length, unlike many other plesiosaurs, which have a long neck and a small head.[49][37] Due to the diagnostic problems of the holotype specimen, most of the anatomical descriptions that follow are based on observations made from more complete specimens subsequently assigned to the genus, mainly from McHenry's thesis published in 2009.[29]

Kronosaurus is one of the largest pliosaurs identified to date,[50] but several estimates as to its exact size have been proposed during his research. As early as 1930, Longman, in his description of propodiums, considered that Kronosaurus would have exceeded in size the imposing Megalneusaurus, a North American pliosaurid dating from the Late Jurassic.[11][1] After the collection of fossils assigned to the genus by the Harvard Expedition, the maximum size of Kronosaurus was set at approximately 12.8 meters (42 ft) long, based on specimen MCZ 1285.[9][22][26][18][51] However, as the reconstruction of the skeleton seems incorrect and elongated, McHenry gives a smaller size of this specimen between 9 and 10.5 meters (30 and 34 ft) long[18] for a weight of 11 t (11 long tons; 12 short tons).[52] These same measurements are seen as the maximum possible estimates of the genus as a whole.[38] Even before McHenry's thesis was published, paleontologist Benjamin P. Kear and marine biologist Richard Ellis proposed comparable estimates in their respective works published in 2003, ranging from 9 meters (30 ft) according to Kear[50] at 10.6 meters (35 ft) according to Ellis.[26]

Skull[edit]

Reconstructed skull

Since the holotype of K. queenslandicus (QM F1609) consists of only a partial mandibular symphysis, very little can be said about it. However, more complete fossil skulls that are assigned to the taxon show unique traits.[50][39][42] The skulls of various known specimens of Kronosaurus vary in size. The holotype, which although partial and fragmentary, comes from a skull which would have measured a total of 1.31 metres (4.3 ft) long. Candidate neotype specimens QM F10113 and QM F18827 have cranial lengths reaching 1.87–1.98 metres (6.1–6.5 ft), respectively.[53] The skull of the Harvard skeleton is estimated to be 2.85 metres (9.4 ft) long.[54][d] The cranial measurements of the last three specimens previously cited surpass in size the skull of any known theropod dinosaurs.[56] The snout and the mandibular rostrum are long and narrow in shape.[50] The eye sockets face posteriorly, where they are located laterally on the anterior half of the skull.[57] The temporal fossae are very large,[57] but does not have an anterior interpterygoid vacuity.[50]

One of the many traits identified as unique in Kronosaurus is that the premaxilla has 4 caniniform teeth.[50][57][37][42] Like its close relatives Brachauchenius and Megacephalosaurus, the mandibular symphysis of Kronosaurus contains up to 6 pairs of teeth.[50][57][37] Each dentary (the tooth-bearing bone in the mandible) have up to 26 teeth.[37]

Classification[edit]

Traditionally, Kronosaurus is classified as a member of the subfamily Brachaucheninae, which consists of pliosaurs that are currently only known during the Cretaceous period. Phylogenetic analyzes consider it close to certain genera such as Brachauchenius or Megacephalosaurus, particularly on the basis of dental comparisons.[58]

The cladogram below is modified from Madzia et al. (2018).[58]

Thalassophonea

Palaeobiology[edit]

Restoration of Kronosaurus chasing a plesiosaur

Fossil stomach contents from Northern Queensland show that Kronosaurus preyed on turtles and plesiosaurs. Fossil remains of large octobrachians[59] have been found in the same area as Kronosaurus. While no direct evidence of the animal predating on these octobrachians exists they fall within the projected size range of prey Kronosaurus would potentially have pursued.[38]

Large, round bite-marks have been found on the skull of an Albian-age Australian elasmosaurid (Eromangasaurus) that could be from a Kronosaurus attack.[60][61]

Paleoecology[edit]

Kronosaurus is known from remains in Australia. The area was covered by a shallow inland sea called the Eromanga Sea which Kronosaurus inhabited.[62] This environment was notably cold, experiencing near freezing temperatures[63] and seasonal ice in certain regions.[64]

See also[edit]

Notes[edit]

  1. ^ The nickname given to this enigmatic character is due to the fact that rumors persisted that he apparently killed a man.[18]
  2. ^ No details were given by Welles as to which Harvard specimen should be designated as a neotype, as several were discovered by the university's expedition. It is, however, very likely that Welles would have been referring to MCZ 1285, given that it is the most complete specimen discovered by the Harvard expedition.[31]
  3. ^ Some specimens like QM F18762, which consists of an almost complete skull, are not analyzed due to the fact that no preparation was made to allow a clear description.[15]
  4. ^ Many previous estimates of the skull size of this skeleton have been proposed throughout descriptions. In 1935, White proposed that the skull would reach a length of 3.72 metres (12.2 ft),[20] while McHenry gives a smaller estimate of 2.21 metres (7.3 ft) in 2009.[55]

References[edit]

  1. ^ a b c d e f g h i j McHenry 2009, p. 25.
  2. ^ a b Kear 2003, p. 292.
  3. ^ a b c d e f g "Kronosaurus". Paleofile.
  4. ^ a b c Albert H. Longman (1924). "A new gigantic marine reptile from the Queensland Cretaceous, Kronosaurus queenslandicus new genus and species". Memoirs of the Queensland Museum. 8: 26–28.
  5. ^ a b c d e f g h i j k Patricia Mather (1986). "The Longman Era". A Time for a Museum : The History of the Queensland Museum 1862-1986. Vol. 24. South Brisbane: Memoirs of the Queensland Museum. p. 138-141. ISBN 978-0-724-21645-1.
  6. ^ McHenry 2009, p. x.
  7. ^ Kear 2003, p. 283.
  8. ^ a b c d e f g h i j k Elizabeth Hall; Max Hall (1985) [1964]. "Kronosaurus, Ruler of the Seas". About the Exhibits (3 ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 8-10.
  9. ^ a b c d e John A. Long (1998). Dinosaurs of Australia and New Zealand and other animals of the Mesozoic era. Cambridge: Harvard University Press. p. 139-142. ISBN 978-0-674-20767-7.
  10. ^ a b c Ben Creisler (2012). "Ben Creisler's Plesiosaur Pronunciation Guide". Oceans of Kansas. Retrieved 26 June 2021.
  11. ^ a b c Albert H. Longman (1930). "Kronosaurus queenslandicus : A Gigantic Cretaceous Pliosaur". Memoirs of the Queensland Museum. 10: 1–7.
  12. ^ McHenry 2009, p. 25-26.
  13. ^ a b c d e f g h McHenry 2009, p. 26.
  14. ^ Albert H. Longman (1932). "Restoration of Kronosaurus queenslandicus". Memoirs of the Queensland Museum. 10: 98.
  15. ^ a b c d McHenry 2009, p. 27.
  16. ^ Albert H. Longman (1935). "Palæontological notes". Memoirs of the Queensland Museum. 10: 236–239.
  17. ^ a b Ralph E. Molnar (1991) [1982], "Fossil reptiles in Australia", in Vickers-Rich, Patricia (ed.), Vertebrate palaeontology of Australasia, Susan Crooke Memorial Collection, Monash University Publications Committee, pp. 631–634, doi:10.5962/bhl.title.60647, OCLC 7390883978, S2CID 84093645
  18. ^ a b c d e f g h i j k l m n o Nancy Pick; Mark Sloan (2004). "Charles Darwin's Buried Treasure & Other Fossil Finds". The Rarest of the Rare : Stories Behind the Treasures at the Harvard Museum of Natural History (1 ed.). New York: HarperResource. p. 68. ISBN 978-0-060-53718-0.
  19. ^ J. Stanley Gardiner (1931). "The Harvard Museum Expedition to Australia". Nature. 128 (3228): 457–458. Bibcode:1931Natur.128..457G. doi:10.1038/128457c0. S2CID 29715877.
  20. ^ a b c d e Theodore E. White (1935). "On the skull of Kronosaurus queenslandicus Longman". Occasional Papers of the Boston Society of Natural History. 8: 219–228.
  21. ^ a b c d Alfred S. Romer; Arnold D. Lewis (1959). "A mounted skeleton of the giant plesiosaur Kronosaurus". Breviora (112): 1–15.
  22. ^ a b c d e f g Michael J. Everhart (2001). "Kronosaurus queenslandicus: Ancient Monarch of the Seas". Oceans of Kansas. Archived from the original on 27 May 2023.
  23. ^ a b "A Giant Plesiosaur". Nature. 184 (4703): 1914. 1959. Bibcode:1959Natur.184Q1914.. doi:10.1038/1841914a0. S2CID 45491683.
  24. ^ a b McHenry 2009, p. 28-29.
  25. ^ a b c McHenry 2009, p. 29.
  26. ^ a b c d Richard Ellis (2003). Sea Dragons: Predators of the Prehistoric Oceans. Lawrence: University Press of Kansas. p. 175-179. ISBN 978-0-7006-1394-6.
  27. ^ McHenry 2009, p. 395.
  28. ^ a b c Girish Tembe; Shameem Siddiqui (2014). "Applications of computed tomography to fossil conservation and education". Collection Forum. 28 (1–2): 47–62. doi:10.14351/0831-0005-28.1.47. S2CID 111536446.
  29. ^ a b c d e f Poropat et al. 2023, p. 150.
  30. ^ Welles 1962, p. 48.
  31. ^ Poropat et al. 2023, p. 148.
  32. ^ McHenry 2009, p. 27-28.
  33. ^ McHenry 2009, p. 28.
  34. ^ Benjamin P. Kear (2005). "Marine reptiles from the Lower Cretaceous (Aptian) deposits of White Cliffs, southeastern Australia: implications of a high latitude, cold water assemblage" (PDF). Cretaceous Research. 26 (5): 769–782. Bibcode:2005CrRes..26..769K. doi:10.1016/j.cretres.2005.04.006. S2CID 128735962.
  35. ^ Benjamin P. Kear (2006). "Plesiosaur remains from Cretaceous high-latitude non-marine deposits in southeastern Australia". Journal of Vertebrate Paleontology. 26 (1): 196–199. Bibcode:2006JVPal..26..196K. doi:10.1671/0272-4634(2006)26[196:PRFCHN]2.0.CO;2. JSTOR 4524550. S2CID 130794388.
  36. ^ Benjamin P. Kear (2016). "Cretaceous marine amniotes of Australia: perspectives on a decade of new research". Memoirs of Museum Victoria. 74: 17–28. doi:10.24199/j.mmv.2016.74.03. S2CID 58903086.
  37. ^ a b c d e Timothy Holland (2018). "The mandible of Kronosaurus queenslandicus Longman, 1924 (Pliosauridae, Brachaucheniinae), from the Lower Cretaceous of northwest Queensland, Australia". Journal of Vertebrate Paleontology. 38 (5): e1511569. doi:10.1080/02724634.2018.1511569. JSTOR 26765770. S2CID 91599158.
  38. ^ a b c McHenry 2009.
  39. ^ a b McHenry 2009, p. 448-449.
  40. ^ a b Leslie F. Noè; Marcela Gómez-Pérez (2021). "Giant pliosaurids (Sauropterygia; Plesiosauria) from the Lower Cretaceous peri-Gondwanan seas of Colombia and Australia". Cretaceous Research. 132: 105122. Bibcode:2022CrRes.13205122N. doi:10.1016/j.cretres.2021.105122.
  41. ^ 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.
  42. ^ a b c Poropat et al. 2023, p. 148-151.
  43. ^ McHenry 2009, p. 257.
  44. ^ Kear 2003, p. 293.
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Bibliography[edit]

External links[edit]

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