Coccolepididae Berg, 1940 sensu Hilton et al. 2004

López-Arbarello, Adriana & Ebert, Martin, 2021, Diversity of chondrostean fish Coccolepis from the Late Jurassic Solnhofen Archipelago, Southern Germany, Acta Palaeontologica Polonica 66 (4), pp. 837-846 : 840-842

Coccolepididae Berg, 1940 sensu Hilton et al. 2004 Genus Coccolepis Agassiz, 1843

Type species: Coccolepis bucklandi Agassiz, 1843 ; Solnhofen Lagerstätte, Germany; lower Tithonian, Upper Jurassic.

Included species: Coccolepis solnhofensis sp. nov. Other species previously assigned to Coccolepis are now excluded from this genus (see Discussion).

Emended diagnosis.—Modified from Hilton et al. (2004) and López-Arbarello et al. (2013). Coccolepidid fish, with the following combination of characters: dermal bones of the skull roof, scales, and fin rays ornamented with mostly regularly arranged sharply pointed, posteriorly directed denticles; opercle is larger than subopercle; lower jaw extremely slender and short, about half the length of the maxilla; single row of large conical teeth on the lower jaw; dorsal fin origin anterior to origin of pelvic fins; large dorsal and pectoral fins, with 41–49 and more than 30 fin rays, respectively.

Coccolepis bucklandi Agassiz, 1843

Figs. 2–4A , 5A .

1843 Coccolepis bucklandi sp. nov.; Agassiz 1843: 300 (vol. 2), pl. 36, figs. 6, 7.

1881 Coccolepis bucklandi Agassiz, 1843 ; Vetter 1881: 37–42, pl. 1: 2.

1991 Coccolepis bucklandi Agassiz, 1843 ; Frickhinger 1991: figure on p. 298.

1992 Coccolepis bucklandi Agassiz, 1843 ; Lambers 1992: 288, pl.1: A.

1995 Coccolepis bucklandi Agassiz, 1843 ; Frickhinger 1995: figure on p. 298.

1999 Coccolepis bucklandi Agassiz, 1843 ; Lambers 1999: 270, fig. 1.

2015 Coccolepis bucklandi Agassiz, 1843 ; Schultze and Arratia 2015: 369–370, figs. 723, 726.

Holotype: MHNN-FOS 361 ( Fig. 2 ). Nearly complete fish in lateral view, missing a portion of its tail and the anteriormost part of the cranium (approximately 75 mm total length). The Neuchâtel specimen has been identified with confidence as the missing type specimen ( Ebert et al. 2021). The shape of the fish and the preserved bones and scales are at the finest detail consistent with Agassiz’ illustration and description of the type specimen.

Type locality: The provenance of the holotype is indicated as “Solnhofen” (written Solenhofen; see Ebert et al. 2021). However, the indication “Solnhofen” in historical labels from the 19 th Century usually vaguely refers to the whole complex of basins within the Solnhofen Archipelago (e.g., Moser et al. 2017). Based on indirect evidence, MHNN FOS 361 most probably comes from one of the localities within the Eichstätt Basin (see Discussion).

Type horizon: Hybonoticeras hybonotum Zone, Altmühltal Formation , lower Tithonian, Upper Jurassic ( Tischlinger and Schweigert 2020).

Material.— Type material and JME-SOS3445 from Blumenberg ( Fig. 3A ), JME-SOS3382 from Workerszell ( Fig. 3B ), and JME-SOS2340 from Schernfeld, all three localities within the Eichstätt Basin; MMG-SNSD BaJ 1845, Eichstätt. All from the Lithacoceras eigeltingense ss Horizon of the Lithacoceras riedense Subzone (Altmühltal Formation, Hybonoticeras hybonotum Zone ).

Diagnosis.—Species of Coccolepis differing from the other species of the genus in the following characters: three distinct preanal scutes; fringing fulcra on pectoral, pelvic and caudal fins; numerous ventral caudal fringing fulcra.

Remarks.—According Article 73 of the International Code of Zoological Nomenclature ( ICZN 1999), the single specimen described and figured by Agassiz (1943), i.e., the MHNN-FOS 361, when creating the nominal taxon Coccolepis bucklandi is the name-bearing type of this species. Considering the original type specimen lost, Hilton et al. 2004) designated the SNSB-BSPG 1904 I 19 as the neotype of C. bucklandi . After relocating the original type specimen, according to Article 75.8 of the ICZN, the rediscovered MHNN-FOS 361 becomes the name-bearing type of Coccolepis bucklandi Agassiz, 1843 , and the neotype proposed by Hilton et al. (2004) is set aside.

Stratigraphic and geographic range.—Although the precise provenance of the holotype is unknown, all the other specimens referred to Coccolepis bucklandi were collected from localities within the Eichstätt Basin of the Solnhofen Lagerstätte, Bavaria, Germany. The limestone beds of the Eicshtätt Basin correspond to the Lithacoceras eigeltingense ss Horizon, Lithacoceras riedense Subzone , Hybonoticeras hybonotum Zone ; Altmühltal Formation, lower Tithonian, Upper Jurassic.

Coccolepis solnhofensis sp. nov.

Figs. 4 , 5 .

Zoobank LSID: urn:lsid:zoobank.org:act:834F1774-D7AB-4953-B0DE-8714E4690F99

2004 † Coccolepis bucklandi Agassiz, 1843 ; Hilton et al. 2004: 213– 231, figs. 2–9, 11–14.

2015 Coccolepis bucklandi Agassiz, 1843 ; Schultze and Arratia 2015: 370, figs. 724–726.

2015 Coccolepis bucklandi Agassiz, 1843 ; Tischlinger and Völkl-Costantini 2015: fig. 178.

Etymology: The species name recalls the Solnhofen Lagerstätte.

Holotype: SNSB-BSPG 1904 I 19. Incompletely preserved acid-prepared specimen figured by Hilton et al. (2004: figs. 3D, 5, 7, 9, 11, 12C, D, 13, 14)

Type locality: Solnhofen Lagerstätte, Bavaria, Germany.

Type horizon: Subplanites rueppellianus Subzone , Hybonoticeras hybonotum Zone, Altmühltal Formation, Tithonian , Upper Jurassic ( Tischlinger and Schweigert 2020).

Material.— Type material and MCZ VPF-5293 ( Hilton et al. 2004: figs. 3A, 4, 6), SNSB-BSPG 1895 I 44 ( Hilton et al. 2004: fig. 3C), SNSB-BSPG AS I 1328 ( Hilton et al. 2004: figs. 8, 12A, B), and SNSB-BSPG 1986 XV 112 ( Hilton et al. 2004: fig. 3B). The provenance of these specimens is discussed below.

Diagnosis.—Species of Coccolepis differing from the other species of the genus in the following characters: one predorsal scute; distinct preanal scales; fringing fulcra on pectoral and caudal fins only; ventral caudal fringing fulcra very slender and few in number.

Description.—See detailed description in Hilton et al. 2004).

Stratigraphic and geographic range.—Specimen SNSB-BSPG 1895 I 44 was collected in the locality of Hummelberg near Solnhofen, within the Solnhofen Basin. The provenance of the other specimens of C. solnhofensis , including the holotype, is only indicated as Solnhofen or lithographic limestone Solnhofen, but it is possible that the species is limited to the Solnhofen Basin ( Fig. 1B ; see Discussion). The limestone beds of the Solnhofen basin correspond to the Subplanites rueppellianus Subzone , upper Hybonoticeras hybonotum Zone of the Altmühltal Formation, lower Tithonian, Upper Jurassic ( Fig. 1C ) ( Tischlinger and Schweigert 2020).

Figures

Fig. 2. Holotype of the chondrostean fish Coccolepis bucklandi Agassiz, 1843 from the Tithonian, Upper Jurassic of the Solnhofen Lagerstätte, Bavaria, Germany. A. MHNN-FOS 361 (TL ~ 75 mm), photograph taken under UV-light, courtesy of Thierry Malvesy (MHNN). Arrows point to fragmentary remains of the preanal scutes. B. Original illustration of Agassiz (1843: pl. 36: 6). Scan courtesy of Eric Hilton (Virginia Institut of Marine Science, Gloucester Point, Virginia, USA).

Fig. 3. Chondrostean fish Coccolepis bucklandiAgassiz, 1843 from the Tithonian, Upper Jurassic of the Solnhofen Lagerstätte, Bavaria, Germany. A. JME- SOS3445, the skull and anterior part of the body are preserved in ventral view. The specimen is twisted at the pelvic fins and the posterior part of the body is preserved in left lateral view (TL = 120 mm). B. JME-SOS3382 (photographed under UV-light), the body is preserved in right lateral view; the skull is slightly twisted and preserved in dorsolateral view (TL = 100 mm).Arrows point to preanal scutes.A, B, Photographs courtesy of Andreas Hecker (JME).

Fig. 4. Fringing fulcra in the chondrostean fishes Coccolepis bucklandi Agassiz, 1843 (A), and Coccolepis solnhofensis sp. nov. (B) from the Tithonian, Upper Jurassic of the Solnhofen Lagerstätte, Bavaria, Germany. A. JME-SOS3445, pelvic fins and preanal scutes (A1). Arrows point to the preserved fringing fulcra; asterisks signal the three preanal scutes. Detail of the ventral margin of the caudal fin (A2). B. SNSB-BSPG AS I 1328, detail of the ventral margin of the caudal fin. Photograph taken under UV-light, courtesy of Helmut Tischlinger (Stammham, Germany).

Fig. 5. Distinct scutes and scales (indicated with the arrows) in the chondrostean fishes Coccolepis bucklandi Agassiz, 1843 (A), and Coccolepis solnhofensis sp. nov. (B, C) from the Tithonian, Upper Jurassic of the Solnhofen Lagerstätte, Bavaria, Germany.A. MHNN-FOS 361 (holotype), fragments of preanal scutes (arrows). Photograph courtesy of Thierry Malvesy (MHNN). B. SNSB-BSPG 1904 I 19 (holotype), preanal scales arrows). C. SNSB-BSPG 1986 XV 112, predorsal scute (arrow).

Fig.1. Geographic and stratigraphic setting. A. Palaeogeographic reconstruction showing the location of the main Upper Jurassic Plattenkalk Lagerstätten in central Europe. The Solnhofen Archipelago is represented with several stars, other Lagerstätten are indicated with dots and italicised names. Abbreviations: AM, Armorican Massif; Bm, Bohemian Massif; LBM, London-Brabant Massif; MC, Massif Central High; PB, Pompeckjsche Block. Redrawn from Viohl (2015: fig.85). B. Palaeogeographic reconstruction of the Solnhofen Archipelago.Orange areas represent sponge/microbial reefs and blue areas represent the basinal facies. Redrawn from Kölbl-Ebert and Cooper (2019: fig. 2). C. Biostratigraphy with ammonite stratigraphic succession of the Lithacoceras riedense and Subplanites rueppellianus subzones of the Hybonoticeras hybonotum Zone (lower Tithonian, Upper Jurassic). Redrawn from Tischlinger and Schweigert (2020: fig. 8).