ARCHIPILIIDAE Haeckel, 1882

Family ARCHIPILIIDAE Haeckel, 1882 sensu Sandin et al. (2019)

Archipilida Haeckel, 1882: 427 [as a tribe]; 1887: 1133, 1134 [as a subfamily].

Trissopilida Haeckel, 1882: 427 [nomen dubium, below a tribe].

Archipiliidae – Campbell 1954: D117. — Petrushevskaya 1986: 132. — Kozlova 1999: 108. — Afanasieva et al. 2005: S291. — Afanasieva & Amon 2006: 138.

Archipiliinae – Campbell 1954: D117. — Afanasieva et al. 2005: S291. — Afanasieva & Amon 2006: 138.

Archipilinae [sic] – Clark & Campbell 1942: 62 (= Archipiliinae); 1945: 33. — Campbell & Clark 1944a: 38. — Chediya 1959: 188. — Petrushevskaya 1981: 247-248.

Nothotripodiscinidae Deflandre, 1972: 231.

Archipilidiae [sic] – Sandin et al. 2019: 201 (= Archipiliidae).

TYPE GENUS. — Archipilium Haeckel, 1882: 427 [type species by subsequent designation (Campbell 1954: D117): Archipilium orthopterum Haeckel, 1887: 1139].

INCLUDED GENUS. — Archipilium Haeckel, 1882: 427 (= Nothotripodiscinus synonymized by Petrushevskaya 1975: 584).

NOMEN DUBIUM. — Trissopilium.

DIAGNOSIS. — Archipiliidae are identified by having only one segment, three feet, and short skirt extension. A three-pointed star rod system and a significant circular frame around the aperture. The cephalic initial spicular system consists of A-, D-, double L- and Ax-rods. The MB is very short or partly degraded. Double l-rod and V-rod are absent. The basal ring is large and significant. It is directly connected to the D- and double L-rods forming three collar pores. These three rods develop into external feet. The basal ring completely merges with the shell’s pore frame. One bifurcated rod may emerge from each of the basal ring’s A- and double L-rod connecting points. These rods form variable arches with other supplemental rods to create the pore frame of the cephalic wall in younger forms. The rods become completely embedded in the thick cephalic wall in fully grown forms. A short skirt-like frame develops and an endoplasm occupies the internal space of the shell. The A-rod, or a pointed MB, are sometimes missing or dissolved.

STRATIGRAPHIC OCCURRENCE. — Late Oligocene-Living.

REMARKS

The overall shape of the Archipiliidae is generally similar to that of genera with three feet, one segment, configurations such as Dimelissidae or Phaenocalpididae. However, Archipiliidae are different from these latter two families by the absence or near absence of an MB and the presence of a significant basal ring. The cephalis is covered by a thick wall in normal Archipilium - specimens but a mesh-like texture similar to the cephalic part of Enneaphormis appears in very young forms of Archipilium (Takahashi 1991: pl. 36, fig. 7; O’Connor 1999: fig. 4.K). A quality image of the cephalic initial spicular system was only published in Nishimura (1990: fig. 21.2) while a schematic illustration was shown in Sandin et al. (2019: supplement 1). A “Living” specimen of Archipilium was illustrated in Suzuki & Not (2015: fig. 8.10.20).