THEOPHORMIDIDAE Haeckel, 1882

Family THEOPHORMIDIDAE Haeckel, 1882

Theophormida Haeckel, 1882: 436 [as a tribe]; 1887: 1313, 1366 [as a subfamily].

Sethophormida Haeckel, 1882: 432 [nomen dubium, as a tribe]; 1887: 1192, 1242, 1243 [as a subfamily].

Sethophorminae [sic] – Clark & Campbell 1942: 72 [nomen dubium] (= Sethophormidinae). — Frizzell & Middour 1951: 29. — Chediya 1959: 205.

Sethophormidae [sic] – Frizzell & Middour 1951: 29 (= Sethophormididae). — Nishimura 1990: 95 (sensu emend.). — Sugiyama 1994: 3-4. — van de Paverd 1995: 225. — Sugiyama 1998: 233.

Theophorminae [sic] – Clark & Campbell 1942: 81 (= Theophormidinae); 1945: 43. — Campbell & Clark 1944a: 47; 1944b: 31. — Chediya 1959: 217.

Sethophormididae – Riedel & Campbell 1952: 667, 669 [nomen dubium]. — Campbell 1954: D124. — Petrushevskaya 1971a: 65- 66; 1971b: 988; 1981: 127; 1986: 133. — Dumitrica 1979: 28. — Takahashi 1991: 108. — Kozlova 1999: 118. — De Wever et al. 2001: 236. — Afanasieva et al. 2005: S293-294. — Afanasieva & Amon 2006: 141.

Sethophormidinae – Riedel & Campbell 1952: 669 [nomen dubium]. — Campbell 1954: D124. — Petrushevskaya 1981: 130; 1986: 133. — Afanasieva et al. 2005: S294. — Afanasieva & Amon 2006: 141.

Theophormididae – Campbell 1954: D132.

Theophormidinae – Campbell 1954: D132.

Enneaphormidinae Petrushevskaya, 1981: 127-128; 1986: 132. — Afanasieva et al. 2005: S294. — Afanasieva & Amon 2006: 141-142.

Theophormidae [sic] – Nishimura 1990: 105 (sensu emend.) (= Theophormididae).

TYPE GENUS. — Theophormis Haeckel, 1882: 436 [type species by subsequent designation (Campbell 1954: D132): Theophormis callipilium Haeckel, 1887: 1367].

INCLUDED GENERA. — Enneaphormis Haeckel, 1882: 432. — Theophormis Haeckel, 1882: 436 (= Astrophormis n. syn.). — Velicucullus Riedel & Campbell, 1952: 669.

INVALID NAME. — Leptarachnium.

NOMINA DUBIA. — Octophormis, Sethophormis, Tetraphormis.

DIAGNOSIS. — A two-segmented, flat shell with a significantly large basal ring that is completely merged, becoming part of the shell’s skeletal frame. A cephalic wall with an arch-like meshwork is observed. The cephalic initial spicular system consists of MB, A-, D-, V-, double L-, and Ax-rods. The double l-rod is absent while the MB is very short or partly degraded. The A-rod is very short, keeping the cephalic wall flat. The V-rod is absent in some members. The D-, V- and double L-rods are horizontally situated, and are near the same height level as MB. Likewise, the basal ring is also horizontally situated close to the MB’s height level. The presence or absence of MB and V-rod limits the number of pores in the basal ring; three collar pores by direct connection to the D- and double L-rods (Enneaphormis), or four collar pores by direct connection with D-, V- and double L-rods (Theophormis and Velicucullus). This results in a three- or four-leafed clover outline. In the case of three collar pores, three rods are arranged at 120 degree-intervals and four rods cross each other orthogonally at angles of 90 degrees.

The endoplasm transparent, very small, and is situated within the basal ring. Algal symbionts are found near or within the space inside the basal ring in Theophormis but no algal symbionts are detected in Enneaphormis.

STRATIGRAPHIC OCCURRENCE. — Middle Paleocene-Living.

REMARKS

The cephalic initial spicular system of all known three genera was photographed for Enneaphormis (Nakaseko & Nishimura 1982: pl. 46, figs 4a-5b; Yeh & Cheng 1990: pl. 4, fig. 5; Sugiyama 1998: pl. 3, figs 5; O’Connor 1999: pl. 3, figs 1-4), Theophormis (Nishimura 1990: figs 21.1, 21.2; Takahashi 1991: pl. 32, fig.10, 12; Sugiyama 1994: pl.1, fig.7), and Velicucullus (Nishimura 1992: pl. 3, fig. 7; O’Connor 1999: pl. 3, figs 1-4). The interpretation of Nishimura (1992: pl. 3, fig. 7) indicated the presence of an MB, double L- and an un-coded rod, but this should be necessary reinterpreted as a D-rod instead of an MB and an un-coded rod instead of a V-rod if we refer to Sugiyama (1994: pl. 1, fig. 7). “Living” and protoplasm images were observed in Enneaphormis (Suzuki & Not 2015; fig. 8.11.30) and Theophormis (Zhang et al. 2018: 10, figs 2.34-2.37).

VALIDITY OF GENERA

Theophormis

Astrophormis was classified into “Sethophormidinae of the Sethophormididae within subsuperfamily Sethopiliilae”, and Theophormis was classified into “Theophormidinae of the Theophormididae within subsuperfamily Theopiliilae” sensu Campbell (1954). Sethophormididae and Theophormididae are both defined by the presence of four to nine or more radial apophyses (Campbell 1954: D124 for the former and D132 for the latter). Both have the same basal shell mouth open (Campbell 1954: D124 for the former and D132 for the latter).Thus, the major difference between the genera Astrophormis and Theophormis is at the subsuperfamily level.“Sethopiliilae” is defined by the division of its shell by a transverse stricture into the cephalis and thorax (Campbell 1954: D122), whereas the “Theopiliilae” shell is divided by two transverse strictures into the cephalis, thorax, and abdomen (Campbell 1954: D129). The supporting illustration of Theophormis shows a thorax that resembles a gown with a very wide skirt (Nishimura &Yamauchi 1984: pl. 26, fig. 5), which suggests later growth in the typeillustration. According to Campbell (1954), Astrophormis has 12 to 20 or more radial ribs on a flat, nearly discoidal thorax and the absence of an apical horn (Campbell 1954: D124). Theophormis has a flat, dilated abdomen with an open mouth and numerous radial ribs (Campbell 1954: D132). The typeillustrations and supporting images for Theophormis and Astrophormis demonstrate their very similar appearance. The name Theophormis was used earlier than Astrophormis.