Thaumastosaurus ("marvelous lizard") is an extinct genus of frogs in the family Pyxicephalidae. Five species are known, all from the Eocene of western Europe, including France, England, and Switzerland. Specimens of the species T. gezei from the Quercy Phosphorites of France are known for their exceptional preservation, providing three-dimensional images of the animal's life appearance.[1]

Thaumastosaurus
Temporal range: Late Eocene, 40–34 Ma
"Mummified" specimens of T. gezei
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Pyxicephalidae
Subfamily: Pyxicephalinae
Genus: Thaumastosaurus
de Stefano, 1903
Species
  • T. botti De Stefano, 1903
  • T. gezei Rage and Roček, 2007
  • T. servatus (Filhol, 1876)
  • T. sulcatus Holman and Harrison, 2003
  • T. wardi Holman and Harrison, 2002
Synonyms
Internal scan of a Thaumastosaurus "mummy"

"Mummified" Thaumastosaurus specimens were first described in the 19th century, named "Rana" plicata (a name later found to be preoccupied, and later reclassified as T. gezei) and "Bufo" serratus (later amended to servatus). Fragmentary remains of a skull described in 1903 were confused for the anterior vertebra of a highly unusual lizard, hence the name Thaumastosaurus. Later analyses found "Thaumastosaurus" to be a frog, and assigned the mummified specimens to it. Other skeletal remains assigned to the genus were later found elsewhere in Europe.[1][2][3]

Initially, based on comparative anatomy, Thaumastosaurus was classified within the superfamily Hyloidea, although this would be evolutionary improbable as the Hyloidea were largely restricted to the Americas at the time. More recent cranial analyses have found it to belong to the Pyxicephalidae, a family that contains several large frogs that are now found only in Africa, and specifically a stem-member of the subfamily Pyxicephalinae. This suggests that the ancestors of Thaumastosaurus evolved in Africa and dispersed to western Europe, then a tropical island group, during the early Paleogene. It may be related to Rocekophryne, a fossil frog known from the Eocene of Algeria. Thaumastosaurus appears to have gone extinct at the end of the Eocene, during the Eocene–Oligocene extinction event as the climate rapidly cooled. Afterwards, it was replaced by the modern ranid frog genus Pelophylax, which colonized Europe from Asia.[1][2][4][5]

Distribution and stratigraphic occurrence of Thaumastosaurus

Five species are known, although some may be conspecific with one another:

  • T. botti De Stefano, 1903 – Eocene of France and Switzerland (possibly synonymous with T. gezei)
  • T. gezei Rage and Roček, 2007[6] – Eocene of France
  • T. servatus (Filhol, 1876) – Eocene of France (likely synonymous with T. gezei)
  • T. sulcatus Holman and Harrison, 2003 – Eocene of England
  • T. wardi Holman and Harrison, 2002 – Eocene of England

References edit

  1. ^ a b c Georgalis, Georgios L; Prendini, Elizabeth; Roček, Zbyněk (2023-07-11). "New information on the Eocene frog Thaumastosaurus (Anura, Pyxicephalidae) from the Phosphorites du Quercy, France". Zoological Journal of the Linnean Society. 199 (3): 744–770. doi:10.1093/zoolinnean/zlad047. ISSN 0024-4082.
  2. ^ a b Lemierre, Alfred; Folie, Annelise; Bailon, Salvador; Robin, Ninon; Laurin, Michel (2021-05-04). "From toad to frog, a CT-based reconsideration of Bufo servatus , an Eocene anuran mummy from Quercy (France)". Journal of Vertebrate Paleontology. 41 (3). Bibcode:2021JVPal..41E9694L. doi:10.1080/02724634.2021.1989694. ISSN 0272-4634. S2CID 244552296.
  3. ^ "Fossil Frog Still Looks Gooey After Over 34 Million Years". Science. 2013-09-27. Retrieved 2023-12-06.
  4. ^ Vasilyan, Davit (2018-08-27). "Eocene Western European endemic genus Thaumastosaurus: new insights into the question "Are the Ranidae known prior to the Oligocene?"". PeerJ. 6: e5511. doi:10.7717/peerj.5511. ISSN 2167-8359. PMC 6118198. PMID 30186689.
  5. ^ Laloy, Fabien; Rage, Jean-Claude; Evans, Susan E.; Boistel, Renaud; Lenoir, Nicolas; Laurin, Michel (2013-09-25). "A Re-Interpretation of the Eocene Anuran Thaumastosaurus Based on MicroCT Examination of a 'Mummified' Specimen". PLOS ONE. 8 (9): e74874. doi:10.1371/journal.pone.0074874. ISSN 1932-6203. PMC 3783478. PMID 24086389.
  6. ^ Rage, Jean-claude; Roček, Zbyněk (2007-06-12). "A new species ofThaumastosaurus(Amphibia: Anura) from the Eocene of Europe". Journal of Vertebrate Paleontology. 27 (2): 329–336. doi:10.1671/0272-4634(2007)27[329:ansota]2.0.co;2. ISSN 0272-4634. S2CID 84541672.