Arachnocorys umbellifera (Haeckel, 1862) Petrushevskaya, 1971

Plate 3, Figs 6A – 8B.

Arachnocorys umbellifera n. sp., Haeckel, 1862, pl. 6, fig. 12.

Acanthocorys (Acanthocoronium) umbellifera Haeckel, Haeckel, 1887, p. 1263 [not figured].

? Acanthocorys umbellifera Haeckel, Cleve, 1899, p. 25, not figured.

Arachnocorys umbellifera Haeckel, Jørgensen, 1905, pl. 18, fig. 107.

Arachnocorys umbellifera Haeckel, Petrushevskaya, 1962, pl. 5, figs. 2–4 (non fig. 1).

Arachnocorys umbellifera Haeckel, Benson, 1966, pl. 24, fig. 20 (non fig. 21).

Arachnocorys umbellifera Haeckel, emend. Petrushevskaya, 1971, pl.65, figs. 5–6; pl.66, figs. 1–4.

Arachnocorys umbellifera Haeckel, Tan and Tchang, 1976, text-fig. 58.

non Arachnocorys umbellifera Haeckel, Benson, 1983, pl. 8, fig. 6.

? Acanthocorys umbellifera Haeckel, Ishitani and Takahashi, 2007, pl. 3, figs. a–b (non fig. c).

Arachnocorys umbellifera Haeckel, Onodera et al., 2011, pl. 8, figs. 8–9 (non fig. 7).

? Acanthocorys umbellifera Haeckel, sensu Cleve 1899, Bjørklund et al., 2014, pl. 10, figs.11a–b.

unknown plagonid group C sp 12 cf, Trubovitz et al., 2020, supplementary data 7.

Remarks. This species has been interpreted differently by authors in the literature. It is probable that several distinct species have been illustrated under the name Arachnocorys umbellifera Haeckel. In an attempt to clarify the species concept, our synonymy most closely follows the concepts and illustrations of Petrushevskaya (1971) and Tan and Tchang (1976). The specimen from Cleve’s collection illustrated by Bjørklund et al. (2014) appears to have a relatively smaller cephalis that is sunken into the thorax, compared to illustrations by other authors. Its apical spine also appears to be stronger than the other illustrated specimens. It is difficult to say with certainty that this specimen belongs to a different species based on only two images, so both Cleve (1899) and Bjørklund et al. (2014) are questioned but not excluded in our synonymy.

Range. Late Miocene—Recent, with greatest abundances from the Late Miocene to Early Pliocene in the EEP (Table 1).