Haplorygma Baliński & Sun, 2010

Vinn, Olev, Mironenko, Aleksandr A. & Wilson, Mark A., 2024, New parasitic organisms in a productid brachiopod Eomarginifera lobata from the lower Carboniferous of the Moscow Basin, Russia, Acta Palaeontologica Polonica 69 (3), pp. 403-410 : 406-407

publication ID	https://doi.org/10.4202/app.01156.2024
persistent identifier	https://treatment.plazi.org/id/039887F3-FFBA-DA67-8155-2D8FFEF3F92C
treatment provided by	Felipe
scientific name	Haplorygma Baliński & Sun, 2010
status

Treatment

Genus Haplorygma Baliński & Sun, 2010

Type species: Haplorygma dorsalis Baliński & Sun, 2010 ; middle Tournaisian, Mississippian, Carboniferous, South China.

Haplorygma productidophilia csp. nov.

Figs. 2B View Fig , 3B View Fig , 4A, D View Fig , 5B View Fig .

ZooBank LSID: urn:lsid:zoobank.org:act:4A7CCE0C-4176-4E91-A96D-9125DC9F617D

Etymology: After occurrence in a productid brachiopod.

Holotype: PIN 5918 View Materials /4, complete tube.

Type locality: Borshchevsky Quarry , Russia (54°25′25.0”N, 36°48′37.3” E) GoogleMaps .

Type horizon: Gurovo Formation (Serpukhovian), Mississippian, Carboniferous.

Material.—Ten variably preserved tubes in Eomarginifera lobata ( Sowerby, 1821) ventral valves ( PIN 5918/2–9).

Diagnosis.—Simple, variably oriented with distal part upturned dorsally, microscopic tubular outgrowth of the inner surface of the secondary shell layer in the ventral valve, with circular aperture and widened base, often within muscle scars.

Description.—Simple, variably oriented with distal part upturned dorsally, microscopic tubular outgrowth of the inner surface of the secondary shell layer of the convex ventral valve of productid brachiopods. The tubes often have a widened base in the form of a small bump. The apertures of the tubes vary from perfectly circular to oval, and in a single case angular. There can be a single keel-like structure in the tube interior. The longer tubes have constant diameter. The structure of the tube wall is microlaminar. The tube wall thickness is often variable around the aperture. The tubular structures mostly occur within the adductor or diductor muscle scars. The diameter of the aperture is greatly variable from 100 to 350 µm. The tubes can grow up to 2 mm long but usually are 250 to 500 µm long. The tube wall is up to 70 µm thick.

Remarks. —This new species resembles most closely Haplorygma dorsalis Baliński & Sun, 2010 , from southern China ( Baliński and Sun 2010: 693, fig. 1A, B) in being a simple tubular outgrowth of the inner surface of the secondary shell layer of a brachiopod. It differs, however, by the larger size and location on the ventral interior. Unlike this new species, H. dorsalis never has a circular aperture, it is never located within muscle scars, and it does not have a widened base.

Stratigraphic and geographic range.— Type locality and horizon only.