Paraseraphs tetanus Jung, 1974

Caze, Bruno, Merle, Didier, Pacaud, Jean-Michel & Saint Martin, Jean-Paul, 2010, First Systematic Study using the Variability of the Residual Colour Patterns: The Case of the Paleogene Seraphsidae (Mollusca, Gastropoda, Stromboidea), Geodiversitas 32 (3), pp. 417-477 : 454

publication ID	https://doi.org/ 10.5252/g2010n3a4
persistent identifier	https://treatment.plazi.org/id/03A69848-FFB2-1E78-FF34-FB93FE80FCB8
treatment provided by	Marcus
scientific name	Paraseraphs tetanus Jung, 1974
status

Treatment

Paraseraphs tetanus Jung, 1974 View in CoL ( Figs 24 View FIG A-F; 25; 26)

Paraseraphs tetanus Jung, 1974: 34-36 View in CoL , pl. 9, fig. 26; pl. 10, figs 1-10, text-fig. 12, 26-28.

Terebellum fusiforme – d’Orbigny 1850: 314, no. 304. — Pictet 1855:pl. 64, fig.2. — Deshayes,1865:470.— Mayer, 1866: 319, 332. — Newton, 1894: 97. — Cossmann, 1904: 43, 44, pl. 2, fig. 10; pl. 3, fig. 4. — Cossmann & Pissarro, 1911: pl. 31, fig. 158-1. Non Lamarck, 1802.

Terebellum View in CoL (s.s.) fusiforme – Cossmann 1889: 96 partim. Non Lamarck, 1802.

Paraseraphs placitus Merle, 1986: 32 View in CoL . Non Jung 1974.

Paraseraphs tetanus View in CoL – Savazzi 1991: 324, fig. 13G. — Le Renard 1992: 6. — Le Renard & Pacaud 1995: 112. — Pacaud & Le Renard 1995: 162. — Pacaud 2008: 724, fig. 2C, D.

TYPE LOCALITY. — Cuise-la-Motte (Oise, France), Ypresian (Cuisian, Lower Eocene).

TYPE MATERIAL. — Holotype (NMB H15409); 3 paratypes (NMB H15408, H15405, H16502).

OTHER MATERIAL EXAMINED. — See Appendix 1.

DESCRIPTION

Shell

Shell up to 38 mm in height and 8 mm in diameter, evolute with straight and almost parallel sides( Fig.24A, C,D,F View FIG ). Suture distinct on the adapical part( Fig.24A, C, D, F View FIG ). Aperture long and narrow.Callus of the inner lip well developed and well delineated.Columella bent backwards near the base of the shell ( Fig. 24B, E View FIG ). Outer lip slightly opisthocline and thickened on the adapical part. Outer lip not reaching directly to the apex, but bent towards the dorsal side of the shell ( Fig. 24B, C, E, F View FIG ). Callus of the inner lip, thin, extending on the spire towards the apex and forming a narrow band parallel to the outer lip. Siphonal notch moderately deep. No sculpture observed.

Colour pattern

The pattern is composed of 2 levels of colouration: dark elements on a lighter background ( Fig. 25 View FIG ). The darker elements are usually very thin and form axial rows of dots ( Fig. 25C, F, I View FIG ) and segments ( Fig. 25K View FIG ). On the subsutural part of the last whorl and on the anal canal, a peculiar pattern can be distinguished. It corresponds to an oblique succession of darker and lighter “patches” ( Fig. 25H, J, L, P, R View FIG ). These “patches” are not true patches as defined in the part terminology, but are the result of the coalescence of axial segments.

VARIABILITY

Among 319 specimens from 5 localities (Cuisian), 304 (95.3%) show a residual pattern under UV light ( Table 1). Th us, these observations provide a good general survey of intraspecific variability of the pattern of this species.

The residual pattern of Paraseraphs tetanus shows strong variability ( Fig. 26 View FIG ). Th e dots are variable in size and shape from axially elongated to circular or triangular shape or indeed completely distorted ( Fig.26I, J View FIG ). Th eir density on the shell, and the degree of coalescence, can be weak to very considerable. Some shells bear only a few dark dots disseminated on the surface ( Fig. 26F, G, K View FIG ). When the density of dots increases, they form some thin axial rows ( Fig. 26D, E, H View FIG ) or, by coalescence, compressed segments ( Fig. 26 View FIG A-C) or sinuous stripes ( Fig. 26 View FIG O- R). In spite of this variability, two representative morphological types can be distinguished (types 1 and 2, Fig. 27 View FIG ). Type 1 corresponds to the most abundant portion of the analysed specimens. The pattern of the type 1 is composed of axial rows of more or less coalescent dark dots ( Fig. 26 View FIG A-F). Type 2 bears some sinuous and more or less discontinuous axial stripes ( Fig. 26 View FIG O-R). Several shells show a morphology intermediate between both types ( Figs 26 View FIG G-K, L-N; 27). Th e relative abundance of these morphologies is given in Figure 27 View FIG . The Figure 26 View FIG illustrates each type described above with several intermediate specimens, showing the impossibility of separating one type from another, as different species.

Kingdom	Animalia
Phylum	Mollusca
Class	Gastropoda
Order	Littorinimorpha
Family	Seraphsidae
Genus	Paraseraphs