Machimosaurus

Last updated

Machimosaurus
Temporal range: 154–130  Ma
Machimosaurus sp.jpg
Machimosaurus mosae cast
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Suborder:† Thalattosuchia
Family:† Machimosauridae
Tribe:† Machimosaurini
Genus:† Machimosaurus
Von Meyer, 1837
Species
  • †M. hugii type Von Meyer (1837)
  • †M. mosaeSauvage and Lienard 1879
  • †M. nowackianus(von Huene. 1938)
  • †M. buffetautiYoung et al., 2015
  • †M. rexFanti et al., 2016 [1]
Synonyms
  • Madrimosaurus hugii( sic )

Machimosaurus is an extinct genus of machimosaurid crocodyliform from the Late Jurassic (Kimmeridgian and Tithonian) and Early Cretaceous. [2] [3] The type species, Machimosaurus hugii, was found in Switzerland. Other fossils have been found in England, France, Germany, Portugal, Switzerland and Tunisia. [2] [4] [5] Machimosaurus rex is the largest named teleosauroid and thalattosuchian, with an estimated length of up to 7.15 m (23.5 ft) (skull length 155 cm (61 in)). [6] Machimosaurus is the largest known crocodyliform of the Jurassic. [2] [3] [4] [6]

Contents

Discovery and species

Illustrations of the three European species Machimosaurus illustration.jpg
Illustrations of the three European species

Christian Erich Hermann von Meyer in 1837 named isolated conical, blunt teeth with numerous longitudinal lines from Switzerland, Madrimosaurus hugii. However, in 1838, realising he had misspelled the name, he emended Madrimosaurus to Machimosaurus, from the Greek machimoi , ancient Egyptian troops deployed during the Ptolemaic Dynasty plus the -saurus suffix, literally meaning "pugnacious lizard". [7] The teeth of Machimosaurus, with their rounded, blunt apex and stout morphology make them characteristic and easily identifiable compared to other teleosaurid teeth. [8]

The type species, M. hugii, is known from the Kimmeridgian of Portugal, Spain, Tunisia and Switzerland. [2] [7] Machimosaurus ferox and M. interruptus were previously considered junior synonyms of M. hugii, [9] [10] but have been recently considered possible synonyms of Machimosaurus mosae. [7]

Krebs (1967), [9] considered M. mosae (Lienard, 1876) to be a junior synonym of M. hugii, but is considered a second valid species of the genus based on a nearly complete skeleton found from the late Kimmeridgian of France. [7] [11]

Two species also placed within Machimosaurus are M. bathonicus and M. rigauxi, from the Bathonian of France. [12] However, these are gracile species, lacking the characteristic blunted teeth of Machimosaurus, and are probably referable to Steneosaurus. [7]

Skull Machimosaurus buffetauti.jpg
Skull

Mark Young and his colleagues [7] [13] made a detailed revision of the genus and recognized four species: M. hugii, M. mosae, M. nowackianus from Harrar, Ethiopia, and a new species, Machimosaurus buffetauti. They hypothesized that Machimosaurus may have been analogous to the Pliocene–Holocene genus Crocodylus in having one large-bodied taxon suited to traversing marine barriers and additional, geographically limited taxa across its range.

The fossilized anterior portion of the lower jaw from the Late Jurassic (Oxfordian or Kimmeridgian) of Ethiopia referred to the pliosaur Simolestes nowackianus , is in fact a large species of Machimosaurus. [14]

In 2016, a new species of Machimosaurus from Douiret Formation in Tunisia was described in the journal Cretaceous Research. Named Machimosaurus rex, it was the largest teleosauroid known at the time, estimated to be 9.6 m (31.5 ft) in length (skull length 155 cm (61 in)) based on a partial skeleton. [3] M. rex was also the youngest teleosauroid known at the time. However, more recent estimates put M. hugii along with M. rex at about 6.9–7.15 m (22.6–23.5 ft) long. [6] The discovery of M. rex indicates that teleosauroid crocodylomorphs survived the extinction event at the end of the Late Jurassic, but did not retain the biodiversity seen in the Jurassic. Moreover, an incomplete specimen from the Barremian of Colombia attributed to Teleosauroidea is not only the youngest known teleosauroid, but also the largest at about 9.6 m (31.5 ft) long. [15]

Palaeobiology

Niche partitioning

From the Kimmeridgian-age, semi-aquatic deposits of Oker, Lower Saxony, Germany two genera of teleosaurids ( Steneosaurus and Machimosaurus) are known, in addition to the neosuchian genera Goniopholis and Theriosuchus . [16] Machimosaurus and Steneosaurus are also found together in the same Tithonian-age deposits of western France. [17]

Diet

Tooth Machimozahn.jpg
Tooth

Bite marks on an early Kimmeridgian sauropod ( Amanzia ) femur from Switzerland match teeth known from Machimosaurus hugii, also found in the same deposits. This suggests either scavenging on the sauropod's corpse, or active predation from the waters edge, much like living crocodilians. [18] Kimmeridgian-age fossil turtles from "Solothurn Turtle Limestone" of northern Switzerland have bite marks, and splintered Machimosaurus teeth imbedded, [19] while fossil turtles from the Late Jurassic of Germany also possess bite marks that match teeth of Machimosaurus found in the same deposit. [20]

Morphofunctional analysis on the skull of Machimosaurus strongly suggests they ate turtles (chelonophagy). [9] [10] Morphological comparison of their teeth also confirms that they are adapted to seizing and crushing hard prey. [8] [21]

Locomotion

Based on the vertebrae (zygapophysial) articulations, Machimosaurus is considered to have lived in open-seas, swimming by lateral undulations of the tail with the limbs used for steering and balancing. Head and neck depressing (downward moving) muscles would have been well-developed, as their attachment site on the skull (basioccipital tubera) were large. This would have greatly assisted Machimosaurus in diving. [9]

See also

Related Research Articles

<i>Dakosaurus</i> Metriorhynchid reptile genus from the Late Jurassic / Early Cretaceous period

Dakosaurus is an extinct genus of crocodylomorph within the family Metriorhynchidae that lived during the Late Jurassic and Early Cretaceous. It was large, with teeth that were serrated and compressed lateromedially. The genus was established by Friedrich August von Quenstedt in 1856 for an isolated tooth named Geosaurus maximus by Theodor Plieninger in 1846. Dakosaurus was a carnivore that spent much, if not all, its life out at sea. The extent of its adaptation to a marine lifestyle means that it is most likely that it mated at sea, but since no eggs or nests have been discovered that have been referred to Dakosaurus, whether it gave birth to live young at sea like dolphins and ichthyosaurs or came ashore like turtles is not known yet. The name Dakosaurus means "biter lizard", and is derived from the Greek dakos ("biter") and σαῦρος -sauros ("lizard").

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

Metriorhynchus is an extinct genus of marine crocodyliform that lived in the oceans during the Late Jurassic. The type species, M. brevirostris was named in 1829 as a species of Steneosaurus before being named as a separate genus by the German palaeontologist Christian von Meyer in 1832. The name Metriorhynchus means "Moderate snout", and is derived from the Greek Metrio- ("moderate") and -rhynchos ("snout").

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

Geosaurus is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous. Geosaurus was a carnivore that spent much, if not all, its life out at sea. No Geosaurus eggs or nests have been discovered, so little is known of the reptile's lifecycle, unlike other large marine reptiles of the Mesozoic, such as plesiosaurs or ichthyosaurs which are known to give birth to live young out at sea. Where Geosaurus mated, whether on land or at sea, is currently unknown. The name Geosaurus means "Mother of Giants lizard", and is derived from the Greek Ge- and σαῦρος -sauros ("lizard"). The name Geosaurus was established by the French naturalist Georges Cuvier in 1824.

<span class="mw-page-title-main">Thalattosuchia</span> Clade of marine crocodylomorphs

Thalattosuchia is a clade of mostly marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution. They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia and records from Thailand and China suggest that some members lived in freshwater. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes. Within Metriorhynchoidea, the Metriorhynchidae displayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin, and probably gave live birth, seemingly uniquely among archosaurs.

<span class="mw-page-title-main">Teleosauridae</span> Extinct family of reptiles

Teleosauridae is a family of extinct typically marine crocodylomorphs similar to the modern gharial that lived during the Jurassic period. Teleosaurids were thalattosuchians closely related to the fully aquatic metriorhynchoids, but were less adapted to an open-ocean, pelagic lifestyle. The family was originally coined to include all the semi-aquatic thalattosuchians and was equivalent to the modern superfamily Teleosauroidea. However, as teleosauroid relationships and diversity was better studied in the 21st century, the division of teleosauroids into two distinct evolutionary lineages led to the establishment of Teleosauridae as a more restrictive family within the group, together with its sister family Machimosauridae.

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

Plesiosuchus is an extinct genus of geosaurine metriorhynchid crocodyliform known from the Late Jurassic of Dorset, England and possibly also Spain. It contains a single species, Plesiosuchus manselii.

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

Pelagosaurus is an extinct genus of thalattosuchian crocodyliform that lived during the Toarcian stage of the Lower Jurassic, around 183 Ma to 176 Ma, in shallow epicontinental seas that covered much of what is now Western Europe. The systematic taxonomy of Pelagosaurus has been fiercely disputed over the years, and was assigned to Thalattosuchia after its systematics within Teleosauridae were disputed. Pelagosaurus measured 2–3 m (6.6–9.8 ft) long.

Cricosaurus is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian of Germany. The name Cricosaurus means "Ring lizard", and is derived from the Greek Krikos- ("ring") and σαῦρος -sauros ("lizard"). It was a relatively small reptile, with C. suevicus and C. araucanensis measuring 2 m (6.6 ft) and 3.2 m (10 ft) in total body length, respectively.

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

Steneosaurus is a dubious genus of teleosaurid crocodyliform from the Middle or Late Jurassic of France. The genus has been used as a wastebasket taxon for thalattosuchian fossils for over two centuries, and almost all known historical species of teleosauroid have been included within it at one point. The genus has remained a wastebasket, with numerous species still included under the label ‘Steneosaurus’, many of which are unrelated to each other.

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

Aeolodon is an extinct genus of teleosaurid crocodyliform reptile from the Late Jurassic (Tithonian) of Germany and France that was initially named as a species of Crocodylus in 1814. Although previously synonymized with Steneosaurus, recent cladistic analysis considers it distantly related to the Steneosaurus type species and the type species is A. priscus, named in 1830 and described in 2020.

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

Mycterosuchus is an extinct genus of teleosaurid crocodyliform from the Middle Jurassic (Callovian) of England. Although previously synonymized with Steneosaurus, recent cladistic analysis considers it distantly related to the Steneosaurus type species.

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

Sericodon is an extinct genus of teleosaurid crocodyliform from the Late Jurassic (Tithonian) of Germany and Switzerland. The genus contains a single species, S. jugleri. Sericodon was placed in 'Clade T' (Aeolodontinae) and was found to be the sister taxon to Bathysuchus, another teleosaurid.

The Tereñes Formation or Tereñes Marl is a Late Jurassic (Kimmeridgian) geologic formation in Asturias, Spain. The grey marls of the formation were deposited in a lagoonal environment at a muddy coast along a temporary inland sea. The lower section of the formation comprises silty and chalky sandstones with desiccation cracks and ripple marks, then becomes a bituminous, prominently ostracod-bearing, pelecypod shell chalk, lime chalk marl and marl. Fossil tracks have been reported from the formation.

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

Torvoneustes is an extinct genus of metriorhynchid thalattosuchian. It is known from skull and postcranial remains found in the Kimmeridge Clay Formation of Dorset and Wiltshire, England, the Virgula Marls of Switzerland and also from Oaxaca, Mexico . The holotype skull of the type species was initially assigned to the species Metriorhynchus superciliosus. Postcranial remains were later discovered from the same quarry as the skull, and then these specimens were recognised as belonging to a new species of Dakosaurus, as D. carpenteri. The species was named to honour Simon Carpenter, an amateur geologist from Frome in Somerset, who discovered the fossils.

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

Macrospondylus is an extinct genus of machimosaurid teleosauroid crocodyliform from the Early Jurassic (Toarcian) of Europe. Fossils are known from the Posidonia Shale of Germany, the Whitby Mudstone of the United Kingdom, and the "schistes bitumineux" of Luxembourg.

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

Bathysuchus is an extinct genus of teleosaurid thalattosuchian from Late Jurassic (Kimmeridgian) deep water marine deposits in England and France. Bathysuchus displays features that suggest it was more pelagic than other teleosaurids, including smoother skull bones and reduced armour plating, similar to the fully marine metriorhynchids. This was possibly an adaptation to rising sea levels during the Kimmeridgian, as its earlier relatives such as Teleosaurus were suited for shallow coasts and lagoon environments.

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

Lemmysuchus is a genus of machimosaurid thalattosuchian from the Middle Jurassic Callovian of England and France. Like many other teleosauroids from Europe, it has had a convoluted taxonomic history.

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

Indosinosuchus is a genus of teleosaurid neosuchian that lived during the Late Jurassic or Early Cretaceous in what is now Thailand. It contains two species, the type species I. potamosiamensis and I. kalasinensis, both recovered from the lower Phu Kradung Formation. It is unique among teleosauroids as it is the only named genus known from a freshwater environment, while most other members of the group are marine. Indosinosuchus is placed in the family Teleosauridae, but has a relatively robust skull that bears resemblance to members of the Machimosauridae. Biomechanical analysis of its mandible and teeth suggest that it would have had a substantial bite force comparable to animals like Lemmysuchus. The two Indosinosuchus species however differ in the speed at which they could open and close their jaws, impacting their respective ecology and possibly explaining how they coexisted in the same environment. All known specimens of this genus were recovered from a single locality, which has been interpreted as a mass death site, possibly caused by a drought or flash flood. The precise age of Indosinosuchus is unclear, as the vertebrate fossils of the Phu Kradung Formation support a Late Jurassic age, while palynological data suggests an Early Cretaceous (Berriasian) age.

<span class="mw-page-title-main">Machimosauridae</span> Extinct family of reptiles

Machimosauridae is an extinct family of teleosauroid thalattosuchian crocodyliforms. The family was first identified in 2016, when fossils of teleosauroid thalattosuchians, including an indeterminate close relative of Lemmysuchus and Machimosaurus, were described from the Middle Jurassic (Bathonian) of Morocco. The family was largely expanded in 2020 when the systematics of Teleosauroidea were re-reviewed. Members of this family generally were larger than the teleosaurids.

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

Andrianavoay is an extinct genus of teleosauroid from the Bathonian Kandreho Formation of Madagascar.

References

  1. ↑ Federico Fanti, Tetsuto Miyashita, Luigi Cantelli, Fawsi Mnasri, Jihed Dridi, Michela Contessi, Andrea Cau. The largest thalattosuchian (Crocodylomorpha) supports teleosaurid survival across the Jurassic-Cretaceous boundary, Cretaceous Research, Available online 10 January 2016.
  2. 1 2 3 4 "Monster-Size Marine Crocodile Discovered". 11 January 2016. Archived from the original on January 12, 2016.
  3. 1 2 3 Fanti, Federico; Miyashita, Tetsuto; Cantelli, Luigi; Mnasri, Fawsi; Dridi, Jihed; Contessi, Michela; Cau, Andrea (2016). "The largest thalattosuchian (Crocodylomorpha) supports teleosaurid survival across the Jurassic-Cretaceous boundary". Cretaceous Research. 61: 263–274. doi:10.1016/j.cretres.2015.11.011. hdl: 11585/529635 .
  4. 1 2 Steel R. 1973. Crocodylia. Handbuch der Paläoherpetologie, Teil 16. Stuttgart: Gustav Fischer Verlag,116 pp.
  5. ↑ Mateus, O. 2013. Crocodylomorphs from the Mesozoic of Portugal and a new skull of eusuchian from the Late Cretaceous. Abstract book of Hwaseong International Dinosaurs Expedition Symposium, South Korea, pp: 66-68.
  6. 1 2 3 Young, MT; Rabi, M.; Bell, MA; Foffa, D.; Steel, L.; Sachs, S.; Peyer, K. (2016). "Big-headed marine crocodyliforms and why we must be cautious when using extant species as body length proxies for long-extinct relatives". Palaeontologia Electronica. 19 (3): 1–14. doi: 10.26879/648 .
  7. 1 2 3 4 5 6 Young, M. T., Hua S., Steel L., Foffa D., Brusatte S. L., Thüring S., Mateus O., Ignacio-Ruiz Omeñaca J., Lepage Y., Havilk P., & Andrade M. B. (2014). Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia). Royal Society Open Science. 1(140222), 1-42.
  8. 1 2 Vignaud, P (1997). "La morphologie dentaire des Thalattosuchia (Crocodylia, Mesosuchia)". Palaeovertebrata. 26 (1/4): 35–59.
  9. 1 2 3 4 Krebs, B (1967). "Der Jura-Krokodilier Machimosaurus H. v. Meyer". Paläontologische Zeitschrift. 41 (1–2): 46–55. doi:10.1007/bf02998548. S2CID   130110535.
  10. 1 2 Buffetaut, E (1982). "Le crocodilien Machimosaurus VON MEYER (Mesosuchia, Teleosauridae) dans le Kimmeridgien de l'Ain". Bulletin Trimestrielle Société de la Géologique Normandie et Amis du Museum, Havre. 69 (1/2): 17–27.
  11. ↑ Hua, S; Vasse, D; Buffetaut, E; Martin, M; Mazin, J-M; Vadet, A (1993). "Un squelette de Machimosaurus mosae Sauvage et Lienard, 1879 (Crocodylia, Thalattosuchia) dans le Kimméridgien du Boulonnais". Comptes Rendus de l'Académie des Sciences, Série II. 317 (6): 851–856.
  12. ↑ Sauvage, H-E (1874). "Mémoire sur les dinosauriens et les crocodiliens des terrains jurassiques de Boulogne-sur-Mer". Mémoires de la Société Géologique de France. Série 2. 10 (2): 1–57.
  13. ↑ Young, M. T., Hua S., Steep L., Foffa D., Brusatte S. L., Thüring S., Mateus O., Ruiz-Omeñaca J. I., Havlik P., Lepage Y., & de Andrade M. B. (2015). Addendum to ‘Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)’. Royal Society Open Science. 2, , Number 2
  14. ↑ Bardet, N; Hua, S (1996). "Simolestes nowackianus HUENE, 1938 from the Late Jurassic of Ethiopia is a teleosaurid crocodile, not a pliosaur". Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 1996: 65–71. doi:10.1127/njgpm/1996/1996/65.
  15. ↑ Cortes D, Larsson HCE, Maxwell EE, Parra Ruge ML, Patarroyo P, Wilson JA. 2019. An Early Cretaceous teleosauroid (Crocodylomorpha: Thalattosuchia) from Colombia. Ameghiniana. doi:10.5710/AMGH.26.09. 2019.3269.
  16. ↑ Karl H-V, Gröning E, Brauckmann C, Schwarz D, Knötschke N.2006. The Late Jurassic crocodiles of the Langenberg near Oker, Lower Saxony (Germany), and description of related materials (with remarks on the history of quarrying the "Langenberg Limestone" and "Obernkirchen Sandstone"). Clausthaler Geowissenschaften5: 59-77.
  17. ↑ Billon-Bruyat J-P, Mazin J-M, Buffetaut E, Tong H, Abit D. 2001. New occurrence of vertebrate remains in the latest Jurassic of western France (Oléron island, Charente-Maritime). 6th European Workshop on Vertebrate Palaeontology - Florence and Montevarchi (Italy) - September 19–22, 2001 Abstract Booklet, p. 19
  18. ↑ Meyer, CA; Thüring, CR (2003). "Dinosaurs of Switzerland". Comptes Rendus Palevol. 2 (1): 103–117. doi:10.1016/s1631-0683(03)00005-8.
  19. ↑ Meyer, CA (1991). "Burial experiments with marine turtle carcasses and their paleoecological significance". PALAIOS. 6 (1): 89–96. Bibcode:1991Palai...6...89M. doi:10.2307/3514956. JSTOR   3514956.
  20. ↑ Tichy, G; Karl, H-V (2004). "The structure of fossil teeth of chelonophagous crocodiles (Diapsida: Crocodylia)". Studia Geologica Salmanticensia. 40: 115–124.
  21. ↑ Massare, JA (1987). "Tooth morphology and prey preference of Mesozoic marine reptiles". Journal of Vertebrate Paleontology. 7 (2): 121–137. doi:10.1080/02724634.1987.10011647.
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.