Genus author:
Smith and Araújo, 2017
Early Jurassic (Sinemurian)
Lyme Bay (the coast between Lyme Regis and Charmouth), UK
Referred material (sp.):
Type species:

Thaumatodracon wiedenrothi

Thaumatodracon weidenrothi
Species author:
Smith and Araújo, 2017
Type specimen:
NLMH 106.058 (skull and cervical series)
Sinemurian, Early Jurassic
Geological formation:
Charmouth Mudstone Formation
Type location:
Lyme Bay (the coast between Lyme Regis and Charmouth), UK
Referred material:

Thaumatodracon is a relatively large rhomaleosaurid from the Lower Jurassic (Sinemurian) of Lyme Bay – the coast between Lyme Regis and Charmouth – UK. The holotype specimen (NLMH 106.058) is an almost complete skull and cervical (neck) series. It has a 60 cm long skull, and based on comparison with other rhomaleosaurids I estimate its total body length to be 6.5 m. The skeleton was discovered in early 1969 by amateur fossil hunter Kurt Wiedenroth and purchased later that year by the Niedersächsisches Landesmuseum, Hannover (Smith and Araújo 2017).

Thaumatodracon was described and named by Ricardo Araújo and myself. The skeleton shares some characters with earlier Hettangian rhomaleosaurids (e.g. Atychodracon, Eurycleidus), and other characters with later Toarcian rhomaleosaurids (e.g. Rhomaleosaurus sensu stricto and Meyerasaurus). Its proportions are also intermediate between Hettangian and Toarcian rhomaleosaurids (Smith and Araújo 2017).

Thaumatodracon has two unique characters (autapomorphies): a pronounced pit on the posterior margin of the dorsal ramus of the squamosal, and a paired anteriorly tapering triangular basioccipital processes, although it is possible these are taphonomic artefacts. It also has the following unique combination of characters.

  • Premaxilla-maxilla sutures parallel immediately anterior to the external nares
  • Frontals contact on the midline
  • Premaxillary rostrum short
  • Five teeth in the premaxilla
  • Gently rounded medially convex prefrontal-frontal suture
  • Articular with prominent dorsally concave medial flange anteromedial to the articular glenoid
  • Robust rod-like axis neural spine with circular cross section
  • Neural spines expanded distally

Thaumatodracon was a top-predator in its ecosystem, and probably hunted cephalopods, fish, and smaller marine reptiles.

The genus name derives from the greek θαύμα (= thávma), meaning ‘wonder’, and δράκων (= drákon), meaning ‘dragon’. This is an intentional nod to the invalid name ‘Thaumatosaurus‘, which was once used interchangeably with Rhomaleosaurus before I made ‘Thaumatosaurus’ a nomen dubium (see my article about that here). However, I really liked the sentiment behind the name ‘wonder reptile’, so redeployed the ‘wonder’ part for Thaumatodracon.

Thaumatodracon wiedenrothi is the type and only known species of Thaumatodracon.

For more information about Thaumatodracon here is my blog article from when our paper was published in 2017:

The preserved parts of the skeleton – the head and neck – are highlighted in dark grey
The holotype specimen, laid out in dorsal view.
Thaumatodracon wiedenrothi (NLMH 106.058); cranial elements articulated in life position. A. Photograph in dorsal view. B. Interpretation of dorsal view. C. Photograph in ventral view. D. Interpretation of ventral view. Abbreviations: ang: angular; atax: atlas-axis complex; bo: basioccipital; bo?: possible anterior process of basioccipital; bs: basisphenoid; c3: third cervical vertebra; cor: facet for coronoid; dpmx: dorsal process of maxilla; exn: external naris; exop: exoccipital-opisthotic; fr: frontal; in: internal naris; jug: jugal; mw: medial wall of premaxilla; mx: maxilla; mx13: thirteenth maxillary alveolus; oc: olfactory canal; pal: palatine; par: parietal; pin: pineal foramen; piv: posterior interpterygoid vacuity; pmx: premaxilla; pmx1: first premaxillary alveolus; pmx5: fifth premaxillary alveolus; ps: parabasisphenoid; pf: postfrontal; po: postorbital; pt: pterygoid; pt?: possible pterygoid; prf: prefrontal; q: quadrate; sa: surangular; sof: suborbital fenestra; sq: squamosal; vom: vomer. Diagonal lines represent broken surfaces; stippling rep- resents matrix; grey areas in B. represent the dorsal surface of the palate; grey areas in D. represent the ventral surface of the skull roof. Scale bar represents 100 mm. Figure and caption from Smith and Araújo (2017).
Thaumatodracon wiedenrothi (NLMH 106.058), region of the mandibular symphysis. A. Photograph in dorsal view. B. Interpretation. C. Photograph in ventral view. D. Interpretation. E. Photograph in right lateral view. F. Interpretation. Abbreviations: bos: raised bosses; ch: diagonal channels; den: dentary; d1: first dentary alveolus; d5: fifth dentary alveolus; d10: tenth dentary alveolus; d15: fifteenth dentary alveolus; sp: splenial; sp?: possible fragment of splenial. Diagonal lines represent broken surfaces, stippling represents matrix. Scale bar represents 50 mm. Figure and caption from Smith and Araújo (2017).
The Lower Saxony State Museum commissioned artist Luzia Soares to create a stylistic impression of Thaumatodracon. Copyright L. Soares 2017