PATULIBRACCHIIDAE Pessagno, 1971

Suzuki, Noritoshi, Caulet, Jean-Pierre & Dumitrica, Paulian, 2021, A new integrated morpho- and molecular systematic classification of Cenozoic radiolarians (Class Polycystinea) - suprageneric taxonomy and logical nomenclatorial acts, Geodiversitas 43 (15), pp. 405-573 : 455-456

Family PATULIBRACCHIIDAE Pessagno, 1971

sensu De Wever et al. (2001)

Patulibracchiinae Pessagno, 1971a: 22 ; 1976: 29. — Feary & Hill 1978: 366. — Baumgartner 1980: 300. — De Wever 1982b: 243. — Yang 1993: 38. — Cordey 1998: 86.

Patulibrachiinae [sic] – nec Ormiston & Lane 1976: 168-169 (= Patulibracchiinae ).

Patulibracchiidae – Baumgartner 1980: 297, 300 ( sensu emend. ). — De Wever 1982b: 241-242. — Sanfilippo & Riedel 1985: 592- 593. — Carter et al. 1988: 39. — Yang 1993: 38. — Dumitrica 1995: 26. — Hollis 1997: 49. — De Wever et al. 2001: 142-143 ( sensu emend. ). — Afanasieva et al. 2005: S284. — Afanasieva & Amon 2006: 126. — Bragin 2007: 1001; 2011: 760.

Patulibracchidae [sic] – Dumitrica 1984: 100-101 (= Patulibracchiidae ).

Patulibracchinae [sic] – Blome 1984: 354 (= Patulibracchiinae ).

Patulibrachiidae [sic] – Cordey 1998: 86 (= Patulibracchiidae ).

TYPE GENUS. — Patulibracchium Pessagno, 1971a: 26 [type species by objective designation: Patulibracchium davisi Pessagno, 1971a: 30 ]

INCLUDED GENERA (Cenozoic only). — Cryptomanicula Dumitrica, 2019: 48. —? Heterosestrum Clark & Campbell, 1945: 21 (= Hexacyclia synonymized by Petrushevskaya & Kozlova 1979: 103). — Trimanicula Dumitrica, 1991: 46 .

DIAGNOSIS. — Skeleton consists of a three-armed shell with an eccentric heptagonal microsphere. The arms unequal with 3-4 canals and one arm having a bracchiopyle.

STRATIGRAPHIC OCCURRENCE. — Early Paleocene-Early Pliocene.

REMARKS

The internal skeletal structure for Cryptomanicula ( Dumitrica 2019: figs 3.f, 3.h, 5.a-5.e, 7.e-7.e) and Trimanicula was already documented ( Dumitrica 1991: pl. 8, figs 9-11; pl. 9, figs 1-13; Dumitrica 2019: figs 7.a, 7.b, 7.f). Cryptomanicula closely resembles Homunculodiscus ( Suttoniidae ). The former genus can be distinguished by the presence of three rods emanating from the central structure, whereas the central part of the latter genus resembles a snowman and consists of two to three large “snowballs” of different sizes or a treefoil chamber without three rods around this central structure.

Heterosestrum is commonly found in the Middle to Upper Eocene and is commonly used as a zonal marker species in the high-latitude northern hemisphere ( Dzinoridze et al. 1976; Petrushevskaya & Kozlova 1979; Kozlova 1999; Popova et al. 2002; Suzuki et al. 2009d). The exact taxonomic position of this genus is uncertain due to the poor knowledge of its internal structure. This genus is well documented with many illustrations that include the equatorial and lateral views ( Petrushevskaya & Kozlova 1979: figs 441-449, 451-457). According to Gorbunov (1979: pl. 13, figs 1a- 1g), this genus may belong to the Heliodiscidae (based on observations of Heterosestrum tschujenko , which shows an eccentrically placed microsphere). However, H. tschujenkio illustrated in Dzinoridze et al. (1976: pl. 24, figs 1-4) resembles a Circodiscidae while Heterosestrum rotundum in Hull (1996: pl. 1, figs 10, 11) resembles Amphitholidae (originally Tholoniidae ). The lateral view of this genus is similar to Phorticiidae (originally Larnacillidae in Dzinoridze et al. 1976: pl. 24, fig. 5; Popova et al. 2002: figs 10.I, 12.O). Suzuki et al. (2009d: pl. 3, fig. 12) interpreted Heterosestrum rotundum as a Lithocycliidae (originally Phacodiscidae ).

VALIDITY OF GENERA

Heterosestrum

The whole appearance of Heterosestrum is nearly the same as that of Hexacyclia, although their internal structures have been so far poorly illustrated. Both these genera are synonymized here until the difference of their internal structures are clear. Heterosestrum is an available name older than Hexacyclia.