Pholidosaurus

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Pholidosaurus
Temporal range: Early Cretaceous, Berriasian–Albian
Pholidosaurus.jpg
Pholidosaurus meyeri skull fossil at the Museum für Naturkunde, Berlin
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Family: Pholidosauridae
Genus: Pholidosaurus
Meyer, 1841
Species
  • P. meyeri(Dunker, 1844)
  • P. purbeckensis? Salisbury, 2002
  • P. schaumburgensisMeyer, 1841 (type)
Synonyms
  • MacrorhynchusDunker, 1844
  • Petrosuchus laevidens Owen, 1878 (vide Andrews, 1913)
  • Steneosaurus purbeckensis? Mansel-Pleydell, 1888

Pholidosaurus is an extinct genus of neosuchian crocodylomorph. It is the type genus of the family Pholidosauridae. Fossils have been found in northwestern Germany. The genus is known to have existed during the Berriasian-Albian stages of the Early Cretaceous. Fossil material found from the Annero and Jydegård Formations in Skåne, Sweden and on the island of Bornholm, Denmark, have been referred to as a mesoeucrocodylian, and possibly represent the genus Pholidosaurus. [1]

Contents

Description

Skull of the possible species Pholidosaurus purbeckensis (originally classed under the genus Petrosuchus) Petrosuchus.jpg
Skull of the possible species Pholidosaurus purbeckensis (originally classed under the genus Petrosuchus)

An early description of the genus by Lydekker (1888) mentioned that the orbit is slightly smaller than the supratemporal fossa, the nasals reach the premaxillae, and the vomer appears on the palate. [2] It is similar in appearance to and about as large as the modern gharial.

Species

The type species of Pholidosaurus is P. schaumburgensis, named in 1841 from the Wealden of Bückeburg, Germany. [2] [3] P. schaumburgensis was named on the basis of a natural mold of part of a thorax discovered in around 1830 from the Berriasian Obernkirchen Sandstein. [4] This mould is known as IMGPGö 741-1. The individual that the mould belonged to is thought to have been around 25 centimetres (9.8 in) in length. [5]

Macrorhynchus is a junior synonym of Pholidosaurus. [6] It was named in 1843 from the same stratigraphic unit and region as P. schaumbergensis, with the type species being M. meyeri. [7] Because M. meyeri bears a strong resemblance to Pholidosaurus schaumburgensis, it is now regarded as a species of Pholidosaurus. It was reassigned to the genus Pholidosaurus in 1887 by Richard Lydekker because of this synonymy, and also because the name Macrorhynchus was preoccupied by a genus of fish named in 1880. [3] P. meyeri differs from P. schaumburgensis in that the bar separating the supratemporal fenestrae is rounded, while in the type species it is rounded. [2]

Misassigned species

Pholidosaurus decipiens was erected for a partial cranium, NHMUK 28432, that was originally assigned to the new genus and species Petrosuchus laevidens by Richard Owen in 1878. [8] Petrosuchus laevidens was based on this cranium and a mandibular ramus called BMNH 41099, both of which were collected from Swanage, England. A later study in 1911 concluded that the material belonged to two different species; NHMUK 28432 was reassigned to Pholidosaurus and NHMUK 41099 was designated the lectotype of Petrosuchus laevidens. The species name decipiens was coined in reference to Owen's oversight, and Petrosuchus is now considered a junior synonym of Goniopholis simus . [5]

Another species from England, P. purbeckensis, was originally described as a species of Steneosaurus in 1888. [9] The holotype is an almost complete cranium, referred to as DORCM G97, missing the anterior portion of the rostrum. The skull was found from either Swanage or the Isle of Purbeck (hence the species name), although the exact locality from which the skull originated is not specified by the author of the original description. [10] This material was also once referred to Macrorhynchus. The author of the 1888 description considered S. purbeckensis an intermediate form between Steneosaurus and Teleosaurus . [9] However, in 2002, a new study showed that S. purbeckensis was conspecific with P. decipiens, creating the new combination Pholidosaurus purbeckensis. [5]

Another species of Pholidosaurus, P. laevis, was named in 1913 from Swanage, based on the partial cranium NHMUK R3414. [11] This has been considered a junior synonym of P. purbeckensis by both Salisbury et al. (1999) and Salisbury (2002). [5] [12]

In an SVPCA abstract, Smith et al. (2016) noted that Pholidosaurus purbeckensis is not congeneric with the type species, and instead is closely related to Fortignathus and members of Dyrosauridae. [13]

Classification

Phylogenetic position of Pholidosaurus
Sereno et al. 2001 [14]
Neosuchia  
Pol 2003 [15]

Richard Lydekker assigned Pholidosaurus to the family Goniopholididae in 1887 along with Hylaeochampsa , Theriosuchus , Goniopholis , and Petrosuchus because the vertebrae are amphicoelus and the orbit communicates with the lateral temporal fossa. [3]

Possible Pholidosaurus tooth (DK164) from the Jydegaard Formation at the Geological Museum in Copenhagen Pholidosaurus tooth.jpg
Possible Pholidosaurus tooth (DK164) from the Jydegaard Formation at the Geological Museum in Copenhagen

Pholidosaurus has often been grouped with other longirostrine, or long-snouted, crocodylomorphs, including dyrosaurids and thalattosuchians. Buckley and Brochu (1999) concluded that Pholidosaurus, Sokotosuchus , Dyrosauridae, and Thalattosuchia formed a longirostrine clade that was the sister taxon to Crocodylia. [16] However, Thalattosuchia was traditionally considered a more basal clade of crocodylomorphs, being a more basal lineage of Mesoeucrocodylia than dyrosaurids or Pholidosaurus, both of which were considered neosuchians. [17] The results of the phylogenetic analysis by Buckley and Brochu (1999) were attributed to the similarity in characters associated with snout elongation seen in these crocodylomorphs, even though these characters may have been independently derived in each group. More recent studies have revealed Thalattosuchia as a more basal clade when dyrosaurids are removed from the data set. [18]

More recent studies show that Pholidosaurus is closely related to the Thalattosuchia, with both taxa closely related to a clade containing Terminonaris and the Dyrosauridae. [19] In a phylogenetic analysis conducted by Sereno et al. (2001), Pholidosaurus was placed as a distant sister taxon to the other longirostrine crocodylomorphs, with Terminonaris and the newly named Sarcosuchus being closely related to one another and Dyrosaurus being the next closest taxon to the group. [14] The later phylogenetic analysis of Brochu et al. (2002) again showed that Pholidosaurus was closely related to Thalattosuchia. In the study, both taxa formed a clade that was the sister taxon to a clade containing Sokotosuchus and Dyrosauridae. [20] Jouve et al. (2006) concluded that Pholidosaurus was closely related thalattosuchians were also included within the family, which would be considered paraphyletic without them. Jouve et al. (2006), like Buckley and Brochu (1999), attributed this result to phylogenetic problems that exist among longirostrine crocodylomorphs due to similarities in their morphology. [21]

Related Research Articles

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

Goniopholis is an extinct genus of goniopholidid crocodyliform that lived in Europe and North America during the Late Jurassic and Early Cretaceous. Like other goniopholidids, it resembled living crocodilians, and probably had a similar ecology as semi-aquatic ambush predators.

<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.

Purranisaurus is an extinct genus of marine crocodyliform from the Middle to Late Jurassic period of Chile and Vaca Muerta of Argentina. Rusconi originally regarded Purranisaurus potens to be a plesiosaur; however, Gasparini demonstrated that it was in fact a metriorhynchid crocodyliform, and that may be a junior synonym of Metriorhynchus. It was about 3.3 m (11 ft) long.

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

Dyrosauridae is a family of extinct neosuchian crocodyliforms that lived from the Campanian to the Eocene. Dyrosaurid fossils are globally distributed, having been found in Africa, Asia, Europe, North America and South America. Over a dozen species are currently known, varying greatly in overall size and cranial shape. A majority were aquatic, some terrestrial and others fully marine, with species inhabiting both freshwater and marine environments. Ocean-dwelling dyrosaurids were among the few marine reptiles to survive the Cretaceous–Paleogene extinction event.

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

Arambourgisuchus is an extinct genus of dyrosaurid crocodylomorph from the late Palaeocene of Morocco, found in the region of Sidi Chenane in 2000, following collaboration by French and Moroccan institutions, and described in 2005 by a team led by palaeontologist Stéphane Jouve. Arambourgisuchus was a large animal with an elongated skull 1 meter in length.

Elosuchus is an extinct genus of neosuchian crocodyliform that lived during the Middle Cretaceous of what is now Africa.

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

Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe, Africa, North America and South America. The pholidosaurids first appeared in the fossil record during the Bathonian stage of the Middle Jurassic. Jouve & Jalil (2020) described postcranial material of a pholidosaurid from the Paleocene (Danian) of Ouled Abdoun Basin (Morocco), representing the most recent record of the family. The authors also reinterpreted putative Maastrichtian dyrosaurid Sabinosuchus as a pholidosaurid, and argued that at least two independent pholidosaurid lineages reached the Maastrichtian, among which one survived the Cretaceous–Paleogene extinction event. Before the publication of this study it was thought that the family became extinct during the Late Turonian stage of the Late Cretaceous.

<span class="mw-page-title-main">Neosuchia</span> Clade of reptiles

Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all crocodylomorphs more closely related to Crocodylus niloticus than to Notosuchus terrestris. Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups. The earliest neosuchian is suggested to be the Early Jurassic Calsoyasuchus, which lived during the Sinemurian and Pliensbachian stages in North America. It is often identified as a member of Goniopholididae, though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic.

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

Hylaeochampsidae is an extinct family of basal eusuchian crocodylomorphs thought to be closely related to the order Crocodylia.

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

Thoracosaurus is an extinct genus of long-snouted eusuchian which existed during the Late Cretaceous and Early Paleocene in North America and Europe.

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

Owenodon is a genus of iguanodontian dinosaur known from a partial lower jaw discovered in Early Cretaceous-age rocks of Dorset, United Kingdom, and possibly also Romania and Spain. The first and only definitive specimen was found in the Lulworth Formation of the Purbeck Limestone Group, dating to the middle Berriasian stage. It was first described by Richard Owen as a species Iguanodon, I. hoggii, honouring naturalist A.J. Hogg who had originally collected the fossil. Owen described the mandible as it was, partially embedded in a limestone block, but it was given to the Natural History Museum, London where it was accessioned as NHMUK PV R 2998 and further prepared. Some damage occurred to a tooth crown and part of the bone while stored in the collections. Redescription of I. hoggii by David Norman and Paul Barrett subsequently transferred the species to Camptosaurus in 2002, as well as tentatively referring other camptosaur-like material from the Purbeck beds to the species. The identity of the species was questioned, with Kenneth Carpenter and Yvonne Wilson, and Greg Paul, separating "C." hoggi from Camptosaurus as an intermediate ornithopod, until Peter Galton named the new genus Owenodon for it in 2009. Galton removed the material assigned by Norman and Barrett from Owenodon, but referred isolated teeth from the Bauxite of Cornet, Romania, and the El Castellar Formation of Spain to O. hoggii. The taxon, believed by Galton to be intermediate between Camptosaurus and Iguanodon, is of uncertain relationships, with the limited material preventing clear understanding of its position within ornithopod evolution. Phylogenetic studies have found Owenodon to be more primitive, equivalent to, or more derived than Camptosaurus, but it is often excluded to improve results.

Phosphatosaurus is an extinct genus of dyrosaurid crocodylomorph. It existed during the early Eocene, with fossils having been found from North Africa in Tunisia and Mali. Named in 1955, Phosphatosaurus is a monotypic genus; the type species is P. gavialoides. A specimen has been discovered from Niger, but it cannot be classified at the species level.

Rhabdognathus is an extinct genus of dyrosaurid crocodylomorph. It is known from rocks dating to the Paleocene epoch from western Africa, and specimens dating back to the Maastrichtian era were identified in 2008. It was named by Swinton in 1930 for a lower jaw fragment from Nigeria. The type species is Rhabdognathus rarus. Stéphane Jouve subsequently assessed R. rarus as indeterminate at the species level, but not at the genus level, and thus dubious. Two skulls which were assigned to the genus Rhabdognathus but which could not be shown to be identical to R. rarus were given new species: R. aslerensis and R. keiniensis, both from Mali. The genus formerly contained the species Rhabdognathus compressus, which was reassigned to Congosaurus compressus after analysis of the lower jaw of a specimen found that it was more similar to that of the species Congosaurus bequaerti. Rhabdognathus is believed to be the closest relative to the extinct Atlantosuchus.

Acherontisuchus is an extinct genus of dyrosaurid neosuchian from Middle to Late Paleocene deposits of Colombia. The only known species is A. guajiraensis, whose name means "Acheron crocodile of the Guajira Peninsula".

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

Tethysuchia is an extinct clade of neosuchian mesoeucrocodylian crocodylomorphs from the late Middle Jurassic to the Early Eocene of Asia, Europe, North America and South America. It was named by the French paleontologist Eric Buffetaut in 1982 as a suborder. Tethysuchia was considered to be a synonym of Dyrosauridae or Pholidosauridae for many years. In most phylogenetic analyses the node Dyrosauridae+Pholidosauridae was strongly supported. De Andrade et al. (2011) suggested that Tethysuchia be resurrected for that node. They defined it as a node-based taxon "composed of Pholidosaurus purbeckensis and Dyrosaurus phosphaticus, their common ancestor and all its descendants". In their analysis they found that the support for Tethysuchia is actually stronger than the support for Thalattosuchia. The following cladogram shows the position of Tethysuchia among the Neosuchia.

<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>Anthracosuchus</i> Extinct genus of reptiles

Anthracosuchus is an extinct genus of dyrosaurid crocodyliform from the Paleocene of Colombia. Remains of Anthracosuchus balrogus, the only known species, come from the Cerrejón Formation in the Cerrejón mine, and include four fossil specimens with partial skulls. Anthracosuchus differs from other dyrosaurids in having an extremely short (brevirostrine) snout, widely spaced eye sockets with bony protuberances around them, and osteoderms that are smooth and thick. It is one of the most basal dyrosaurids along with Chenanisuchus and Cerrejonisuchus.

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

Coelognathosuchia is an extinct clade of neosuchian crocodyliforms that includes all taxa more closely related to the family Pholidosauridae than to Bernissartia fagesii or Eusuchia. Martin et al. (2014) named the clade after finding goniopholidids and pholidosaurids to group together in their phylogenetic analysis of crocodyliform evolutionary relationships. In their analysis, Pholidosauridae was monophyletic and Goniopholididae was paraphyletic, being an assemblage of successively more basal taxa within Coelognathosuchia. Coelognathosuchia itself was positioned near the base of the larger clade Neosuchia as the sister group to a clade containing the Early Cretaceous neosuchian Bernissartia and Eusuchia, the group that includes all modern crocodilians and their closest extinct relatives.

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

Brachiosuchus is an extinct genus of dyrosaurid crocodyliform known from the Late Cretaceous Kababish Formation of Sudan. It contains a single species, Brachiosuchus kababishensis.

Fortignathus is an extinct genus of dyrosaurid or peirosaurid crocodylomorph known from the Late Cretaceous Echkar Formation in Niger. It contains a single species, Fortignathus felixi, which was originally named as a species of Elosuchus in 2002.

References

  1. Schwarz-Wings, D.; Rees, J.; Lindgren, J. (2009). "Lower Cretaceous Mesoeucrocodylians from Scandinavia (Denmark and Sweden)". Cretaceous Research. 30 (5): 1345–1355. Bibcode:2009CrRes..30.1345S. doi:10.1016/j.cretres.2009.07.011.
  2. 1 2 3 Lydekker, R. (1888). "Crocodilia". Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History): The orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynochocephalia, and Proterosauria. London: Trustees of the British Museum. pp. 42–130.
  3. 1 2 3 Lydekker, R. (1887). "Note on the Hordwell and other crocodilians". Geological Magazine. 4 (7): 307–312. Bibcode:1887GeoM....4..307L. doi:10.1017/S001675680019377X. S2CID   140634029.
  4. Meyer, H. (1841). "Pholidosaurus schaumburgensis ein Saurus aus dem Sandstein der Wald-Formation Nord-Deutschlands". Neues Jahrbuch für Mineralogie, Geologie und Paläontologie. 4: 443–445.
  5. 1 2 3 4 Salisbury, S. W. (2002). "Crocodilians from the Lower Cretaceous (Beriassian) Purbeck Limestone Group of Dorset, Southern England". In A. R. Milner; D. J. Batten (eds.). Life and environments in Purbeck times. Special Papers in Palaeontology. Vol. 68. Wiley-Blackwell. pp. 121–144.
  6. Mook, C. C. (1934). "The evolution and classification of the Crocodilia". The Journal of Geology. 42 (3): 295–304. Bibcode:1934JG.....42..295M. doi:10.1086/624165. S2CID   128568052.
  7. Dunker, W. (1844). "Ueber den norddeutschen sogenannten Walderton und dessen Versteinerungen". Programm der Casseler Gewerbeschule.
  8. Owen, R. (1878). "Monograph on The Fossil Reptilia of the Wealden and Purbeck Formations, Supplement no. VII. Crocodilia (Goniopholis, Pterosuchus, and Suchosaurus)". Palaeontographical Society Monograph: 1–15.
  9. 1 2 Mansel-Pleydell, J. C. (1888). "Fossil reptiles of Dorset". Proceedings of the Dorset Natural History and Antiquarian Field Club. 9: 1–40.
  10. Woodward, A. S.; Sherbron, C. D. (1980). A catalogue of British Fossil Vertebrata. Vol. 8 volumes. London. pp. 396pp.{{cite book}}: CS1 maint: location missing publisher (link)
  11. Andrews, C. W. (1913). "On the skull and part of a skeleton of a crocodile from the Middle Purbeck of Swanage, with the description of a species (Pholidosaurus laevis), and a note on the skull of Hylaeochampsa". Annals and Magazine of Natural History. 8: 485–494. doi:10.1080/00222931308693345.
  12. Salisbury, S. W.; Willis, P. M. A.; Peitz, S.; Sander, P. M. (1999). "The crocodilian Goniopholis simus from the Lower Cretaceous of northwestern Germany". Special Papers in Palaeontology. 60: 121–148.
  13. Thomas J. Smith, Lorna Steel, and Mark T. Young, 2016. Re-evaluation of Pholidosaurus purbeckensis (Crocodyliformes: Tethysuchia) from the Early Cretaceous of England, with implications for the evolution of Pholidosauridae and Dyrosauridae. Symposium of Vertebrate Palaeontology and Comparative Anatomy 2016 Abstract Book. p. 29. "Archived copy" (PDF). Archived from the original (PDF) on 2016-09-15. Retrieved 2016-08-24.{{cite web}}: CS1 maint: archived copy as title (link)
  14. 1 2 Sereno, P. C.; Larsson, H. C. E.; Sidor, C. A.; Gado, B. (2001). "The giant crocodyliform Sarcosuchus from the Cretaceous of Africa" (PDF). Science. 294 (5546): 1516–1519. Bibcode:2001Sci...294.1516S. doi:10.1126/science.1066521. PMID   11679634. S2CID   22956704.
  15. Pol, D. (2003). "New remains of Sphagesaurus huenei (Crocodylomorpha: Mesoeucrocodylia) from the Late Cretaceous of Brazil". Journal of Vertebrate Paleontology. 23 (4): 817–831. Bibcode:2003JVPal..23..817P. doi:10.1671/A1015-7. S2CID   86592576.
  16. Buckley, G. A.; Brochu, C. A. (1999). "An enigmatic new crocodile from the Upper Cretaceous of Madagascar". Special Papers in Palaeontology. 60: 149–175.
  17. Hill, R. V.; McCartney, J. A.; Roberts, E.; Bouaré, M; Sissoko, F.; O'Leary, M. A. (2008). "Dyrosaurid (Crocodyliformes: Mesoeucrocodylia) fossils from the Upper Cretaceous and Paleogene of Mali: implications for phylogeny and survivorship across the K/T Boundary" (PDF). American Museum Novitates (3631): 19pp.
  18. Buckley, G. A.; Brochu, C. A.; Krause, D. W.; Pol, D. (2000). "A pug-nosed crocodyliform from the Late Cretaceous of Madagascar". Nature. 405 (6789): 941–944. Bibcode:2000Natur.405..941B. doi:10.1038/35016061. PMID   10879533. S2CID   4426288.
  19. Wu, X.-C.; Russell, A. P.; Cumbaa, S. L. (2001). "Terminonaris (Archosauria: Crocodyliformes): new material from Saskatchewan, Canada, and comments on its phylogenetic relationships". Journal of Vertebrate Paleontology. 21 (3): 492–514. doi:10.1671/0272-4634(2001)021[0492:TACNMF]2.0.CO;2. S2CID   86206630.
  20. Brochu, C. A.; Bouare, M. L.; Sissoko, F.; Roberts, E. M.; O'Leary, M. A. (2002). "A dyrosaurid crocodyliform braincase from Mali" (PDF). Journal of Paleontology. 76 (6): 1060–1071. doi:10.1666/0022-3360(2002)076<1060:ADCBFM>2.0.CO;2.
  21. Jouve, S.; Iarochène, M.; Bouya, B.; Amaghzaz, M. (2006). "A new species of Dyrosaurus (Crocodylomorpha, Dyrosauridae) from the early Eocene of Morocco: phylogenetic implications". Zoological Journal of the Linnean Society. 148 (4): 603–656. doi: 10.1111/j.1096-3642.2006.00241.x .