Sclerocephalus haeuseri, GOLDFUSS, 1847

Schoch, Rainer R. & Witzmann, Florian, 2009, Osteology and relationships of the temnospondyl genus Sclerocephalus, Zoological Journal of the Linnean Society 157 (1), pp. 135-168 : 141-143

SCLEROCEPHALUS HAEUSERI GOLDFUSS, 1847

1847 Sclerocephalus haeuseri ; Goldfuss, pp. 13–16, pl. 4, figs 1–3.

1858 Sclerocephalus häuseri ; Meyer, pp. 212–215, pl. 15, fig. 9.

1889 Sclerocephalus häuseri ; Ammon, pp. 41–78, 84–91, tables 1, 2: 1–6, 3: 1, 5: 2–8.

1926 Sclerocephalus haeuseri ; Broili, pp. 199–221, figs 1, 8.

1947 Sclerocephalus häuseri ; Romer, p. 137, fig. 23.

1972 Sclerocephalus sp. ; Boy, pp. 71–78, figs 56–61, 69E.

1988 Sclerocephalus haeuseri ; Boy, p. 109,

figs 1–11.

2000 Sclerocephalus haeuseri ; Schoch & Milner, p. 50, figs 42, 43.

2003 Sclerocephalus sp. ; Schoch, figs 2, 4.

2004 Raumbachia compressa; Krätschmer, p. 6, figs 2–10 ( Krätschmer, 2004a).

2004 Pfarrwaldia jeckenbachensis; Krätschmer, p. 18, figs 11–21 ( Krätschmer, 2004a).

2006 Rehbornia klauswaldensis; Krätschmer, p. 5, figs 1–10.

2007 Sclerocephalus haeuseri ; Boy, p. 262, figs 1–3.

Neotype: GPIM-N 1203 ( Fig. 3C , 5C ), as determined by Boy (1988). A large skull (240-mm long) and trunk skeleton, exposing the axial skeleton entirely, most parts of the girdles, and the femur.

Type locality: Pfarrwald at Heimkirchen, Rheinland- Pfalz, Germany.

Type horizon: Pfarrwald Black Shale, Kappeln Unit (L-O 9), Odernheim Subformation, Meisenheim Formation, Autunian (Lower Rotliegend), lowermost Permian ( Fig. 1B ).

Stratigraphical range: Lower part of Quirnbach Formation (Q1) through uppermost part of Meisenheim Formation (L-O 10 of Boy & Fichter, 1982). The lower part of this section probably falls into the uppermost Carboniferous, whereas the Papelberg-Tuff within L-O 6 has been dated to 297 Mya ( Königer et al., 2002), thus most of the occurrences of S. haeuseri fall into the lowermost Permian ( Fig. 1 ). Sclerocephalus haeuseri is the single large temnospondyl found in the Quirnbach Formation through the Odernheim Black Shale (L-O 8), despite some morphological changes that can be traced through this sequence; in the Kappeln Black Shale (L-O 9), it is abundant, but co-occurs with two other species, Sclerocephalus nobilis ( Krätschmer & Resch, 2005) and Cheliderpeton lellbachae ( Krätschmer, 2006) , whereas in the Humberg Black Shale it becomes rare, and co-occurs with two other species, Cheliderpeton latirostre ( Jordan, 1849) and Archegosaurus decheni Goldfuss, 1847 . (See Fig. 1B for stratigraphical ranges).

Geographic range: Q1, L-O 3, St. Wendel ( Broili, 1926; Théobald, 1958); L-O 6, Grumbach, Lauterecken (Windhof) ( Ammon, 1889), Desloch, Jeckenbach, Raumbach, Rehborn, Niederkirchen ( Boy, 1988); L-O 7, Erdesbach (Hölle) ( Schoch, 2003); L-O 8, Odernheim, Rehborn (Hasenkopf), Langenthal, Albessen, Messersbacherhof; L-O 9, Kappeln, Klauswald/ Odernheim, Niedernhausen, Heimkirchen (Pfarrwald); L-O 10, Gresaubach, Humberg/Odernheim ( Fig. 1B ). See Boy (1987) and Krätschmer (2004b). (See Fig. 1A for geographic ranges, and Figs 3A–C , 5A–C for specimens from different horizons).

Comment: Boy (1988) first correlated the Pfarrwald Unit (type horizon) with the top of the Meisenheim Formation (L-O 10 of Boy & Fichter, 1982). Further geological fieldwork suggested instead that it falls into the L-O 9 member of the sequence ( Boy et al., 1990, contra Krätschmer, 2004a).

Validity of S. haeuseri: Recently, Krätschmer (2004a) questioned the validity of S. haeuseri Goldfuss, 1847 . He explicitly referred to the lack of diagnostic features in Goldfuss’ type specimen, arguing this might have belonged to any of the taxa Krätschmer (2004a) subsequently erected in his paper. However, as the type specimen was lost in World War II, Boy (1988) had correctly determined a neotype (GPIM-N 1203), choosing a specimen found by Jürgen Fichter at the type locality and in the type horizon. Based on this specimen, Boy (1988) properly diagnosed the genus Sclerocephalus Goldfuss, 1847 and the species S. haeuseri Goldfuss, 1847 . This occurred in full agreement with the procedure laid out by the International Code of Zoological Nomenclature (ICZN). As the neotype shows all critically diagnostic characters, and Boy’s (1988) description and illustrations addressed these features, the validity of S. haeuseri Goldfuss, 1847 is not challenged. Krätschmer’s (2004a) erection of the taxon Pfarrwaldia jeckenbachensis Krätschmer, 2004 for the neotype (among other specimens) therefore created a subjective junior synonym of S. haeuseri .

Recently erected genera: In arguing against the validity of S. haeuseri, Krätschmer (2004a) erected a total of four new genera, Pfarrwaldia, Raumbachia, Rehbornia, and Jeckenbachia. Our findings indicate that most of these are likely to form ontogenetic stages of the same taxon: Raumbachia is identical with the medium-sized late juveniles and adults of S. haeuseri (skull length 100–150 mm), Pfarrwaldia represents the largest adults (skull length 180–240 mm), and Jeckenbachia is based on a distorted skeleton of a juvenile. Rehbornia is indeed different from all Sclerocephalus specimens studied by us, and will be analysed in a subsequent paper on C. latirostre . Krätschmer (2004a) highlighted differences in trunk length relative to skull length between Raumbachia and Pfarrwaldia, which we believe result from ontogeny. Schoch (2003) reported that the trunk length increased during early larval development relative to the skull in Sclerocephalus , and our studies of adults revealed that this trend was continued into adult life. Krätschmer’s (2004a) generic distinction was also based on divergent presacral counts, 24 in Raumbachia and 25 in Pfarrwaldia; in re-examining his material and additional specimens, we found that most specimens attributed to either species have 25 presacral vertebrae.

Chronosubspecies: Boy (1988) erected two chronosubspecies for S. haeuseri : S. haeuseri haeuseri from the topmost horizon (L–O 10) and S. haeuseri jeckenbachensis from L–O 6 to L–O 9. Although we find this perspective fruitful, we have not adopted Boy’s concept here, because our morphometric data indicate that the story is probably more complicated, requiring a principal components analysis of numerous features, which forms the scope of a separate project. Steyer (2000a) further argued that the features used by Boy (1988) to define the chronosubspecies were too variable, and that the hypothesis was in need of statistical testing, a view that we concur with here.

Diagnosis: Autapomorphies, as contrasted with other Sclerocephalus species ( Figs 4 , 5A–C ).

1. Squamosal narrower than in other species.

2. Skull outline wide-parabolic with convex lateral margins.

3. Deeply concave posterior skull margin with extensive postparietal flange.

4. Lacrimal anteriorly foreshortened, reaching only 60% of the length of the nasal.

Figures

Figure 1. A, topography and geology of the Saar-Nahe Basin, with the most important localities yielding Sclerocephalus marked. B, stratigraphy of the Rotliegend section in the Saar-Nahe Basin, with the range of Sclerocephalus species and their maximum adult sizes listed (for more details see Table 1).

Figure 3. Original material of large adult specimens of Sclerocephalus haeuseri: A, skull of POL-F 002, L–O 10 (dorsal view); B, skull of GPIM-N 1190, L–O 8 (dorsal view, with lateral lines); C, skull of GPIM-N 1203, L–O 9 (dorsal view); D, tail skeleton with skin preservation and bony scales (SMNS 90055); E, forearm and manus (SMNS 90055); F, complete skeleton (SMNS 90055).

Figure 4. Skull reconstruction of Sclerocephalus haeuseri: A, dorsal view; B, ventral view; C, lateral view; D, occipital view; E, mandible in lingual view; F, mandible in labial view. Based on BSPHM-1981 I 99, SMNS 81791, and other specimens from the Jeckenbach Black Shale (L–O 6). Please refer to the text for the list of abbreviations.

Figure 5. Skull roofs of well-preserved specimens of Sclerocephalus from different horizons: A, S. haeuseri BSPHM-1981 I 99 (L–O 6); B, S. haeuseri SMNS 90055 (L–O 6); C, S. haeuseri neotype, GPIM-N 1203 (L–O 9); D, S. jogischneideri FG 321/1/129 (Thuringian Basin); E, S. bavaricus MB.Am.442 (Altenglan Formation); F, S. nobilis NHMM-PW 2005/2Ls (L–O 9).