Stachyodes costulata Lecompte, 1952

Huang, Jiayuan, Liang, Kun, Wang, Yue, Kershaw, Stephen, Jeon, Juwan, Li, Yue & Qie, Wenkun, 2022, Stromatoporoids from a Middle Devonian reef in South China and their palaeoecological implication, Acta Palaeontologica Polonica 67 (3), pp. 711-736 : 728

Stachyodes costulata Lecompte, 1952

Fig. 10.

1952 Stachyodes costulata sp. nov.; Lecompte 1952: 309, pl. 64: 3; pl. 65: 1–4.

1959 Stachyodes costulata Lecompte, 1952 ; Gogolczyk 1959: 372, pl. 4: 3; pl. 5: 1–3.

1963 Stachyodes costulata Lecompte, 1952 ; Stearn 1963: 660, pl. 86: 4, 5.

1966 Stachyodes costulata Lecompte, 1952 ; Klovan 1966: 31, pl. 9: 1–6.

1970 Stachyodes costulata Lecompte, 1952 ; Stearn and Mehrotra 1970: 18, pl. 4: 3, 4.

1971 Stachyodes costulata Lecompte, 1952 ; Zukalová 1971: 101, pl. 34: 5, 6.

1974 Stachyodes costulata Lecompte, 1952 ; Khromykh 1974: 62, pl. 16: 1; pl. 17: 2

1979 Stachyodes costulata Lecompte, 1952 ; Yang and Dong 1979: 81, pl. 46: 9, 10.

1984 Stachyodes costulata Lecompte, 1952 ; Cockbain 1984: 28, pl. 19: a–d; pl. 20: a.

1984 Stachyodes costulata Lecompte, 1952 ; Dong and Wang 1984: 268, pl. 20: 3a, b.

1988 Stachyodes costulata Lecompte, 1952 ; Khromykh and Hung 1988: 34, pl. 16: 6

1989 Stachyodes costulata Lecompte, 1952 ; Dong in Dong et al. 1989: 174, pl. 2: 3a–d.

1992 Stachyodes costulata Lecompte, 1952 ; Dong and Liu 1992: 172, pl. 4: 5a, b.

1999 Stachyodes costulata Lecompte, 1952 ; Mistiaen 1999: 39.

2020 Stachyodes costulata Lecompte, 1952 ; Huang et al. 2020: 7, text-fig. 5E.

Material.— 57 specimens from the Givetian (Middle Devonian) Jiwozhai reef, Dushan Formation , Dushan, Guizhou, South China, with two typical specimens ( NIGP 177058 and NIGP 177059 ) illustrated .

Description.—Skeletons are dendroid, with some in situ specimens growing from laminar into erect columnar (Fig. 10A 1), but preserved as fragmented branches in most specimens. The branches are commonly 4–5 mm in diameter, up to 14 mm. In longitudinal section, the skeleton consists of dark thin pachystromes and thick pachysteles (Fig. 10A). In the central zone, the structure is relatively undifferentiated, with astrorhizal canal, 0.4 mm in diameter (Fig. 10A 1). In the peripheral zone, the structure is well differentiated. Pachysteles radiate from the central area and emerge perpendicularly to the surface, with a width of 0.2 mm. Pachystromes distributed as arches, spacing 7–8 per 2 mm, 0.02 mm in thickness (Fig. 10A 2, A 3). Galleries are circular, perpendicular to the surface, 0.1–0.2 mm in diameter (Fig. 10A 3). In tangential section, pachysteles interconnect to form a regular closed network in the central zone, and gradually radiate to the peripheral zone (Fig. 10B 1). In the marginal zone, pachystromes distributed as concentric circles. The microstructure is apparently striated (Fig. 10A 2, A 3, B 2).

Remarks.—The present species is consistent with Stachyodes costulata Lecompte, 1952 , due to the dense distributed of pachysteles. It differs from Stachyodes radiata Lecompte, 1952 , in having a relatively undifferentiated structure in the central zone.

Stratigraphic and geographic range.—Givetian (Middle Devonian) of Queensland, Australia and Yukon, Canada; Givetian to lower Frasnian (Middle–Upper Devonian) of the Holy Cross Mountains, Poland; Givetian to Frasnian (Middle–Upper Devonian) of Yunnan, Guangxi, and Guizhou provinces, South China and Central Mountains, Afghanistan; Middle–Upper Devonian of Alberta, Canada; lower Frasnian (Upper Devonian) of Moravian Karst, Czech Republic; upper Frasnian (Upper Devonian) of the Dinant Basin, Belgium; Frasnian (Upper Devonian) of Namur Basin, Belgium; Frasnian (Upper Devonian) of Omolon, Russia; Frasnian (Upper Devonian) of Kerman Province, Iran, Canning Basin, Australia; Upper Devonian of northern and central Vietnam and Ulachan Mountains, Russia ( Mistiaen 1999).