Polysphenodon muelleri Jaekel, 1911

Sues, Hans-Dieter & Schoch, Rainer R., 2025, Synopsis of the Triassic reptiles from Germany, Fossil Record 28 (2), pp. 411-483 : 411-483

Polysphenodon muelleri Jaekel, 1911

Holotype.

MB. R. 1302 , gutta-percha casts and plaster molds of ‘ dorsal’ and ‘ ventral’ blocks with impressions of a partial skeleton comprising an incomplete skull, series of caudal vertebrae, and much of the left forelimb and hindlimb. The original holotype has been lost since the 1930 s ( Carroll 1985).

Type locality.

Drill core from a borehole at 775 m depth in strata of the Middle Keuper Subgroup. Near Fallersleben (now part of the city of Wolfsburg), Lower Saxony.

Type horizon.

The precise stratigraphic horizon was apparently not recorded. Age: Late Triassic (Carnian or Norian).

Diagnosis.

Distinguished by the following combination of features: antorbital portion of skull proportionately very short; supratemporal fenestra distinctly shorter than orbit; parietal table wider than interorbital distance; and teeth small, obtusely conical ( Fraser and Benton 1989).

Comments.

Jaekel (1911: fig. 159) only presented a diagrammatic reconstruction of the cranium in palatal view and labeled it “ Polysphenodon Mülleri ” in the figure legend. He never documented the fossil. F. Huene (1929), Carroll (1985), and Fraser and Benton (1989) provided descriptions of the holotype based on casts. The phylogenetic analyses by Herrera-Flores et al. (2018) and DeMar et al. (2022) found Polysphenodon muelleri as the earliest-diverging eusphenodontian.

References.

Jaekel (1911), F. Huene (1929), Carroll (1985), Fraser and Benton (1989), Herrera-Flores et al. (2018).