PROC. R. SOC. VICT. vol. 99, no. 1, 37-50, March 1987 BRACHIOPODS FROM CARBONATE SANDS OF THE AUSTRALIAN SHELF By J. R. R ichardson Museum of Victoria, 285 Russell Street, Melbourne, Vic. 3000. A bstract : Three new genera, Anakinetica and Parakinetica (Terebratulida, Terebratellidae, M agadinea) and Aulites (Rhynchonellida, Cryptoporidae), and 2 new species, Parakinetica stewarti and Magadinella mineuri, are described. All 5 species are found in biogenic sands of the Australian shelf and differ in their adaptations for life in these sediments. Magadinid species use the pedicle to move individuals so that a stable position at the sediment/water interface is maintained. The rhynchonellid is a sedentary form fixed by the pedicle to the undersurfaces of free-living bryoZoan species. Magadinid species are the dominan t brachiopods in Australian shelf sediments in notewo rthy contrast to their absence in New Zealand and Antarctic shelf faunas. Living brachiopods in southern seas are not confined SYSTEMATICS to rocky coastlines and reefs. In the A ntarctic and Suban- Superfamily Terebrate llacea King 1850 tarctic (Foster 1974) and in New Zealand (Richardso n Family Terebratellidae King 1850 1981a) they are the dom inant or co-dom inant m acroin ­ Subfamily M agadinae Davidson 1886 vertebrates in a variety of depositional environm en ts. Spe­ cies within the Subfamily Terebratellinae are the D iagnosis : Differentially thickened Terebratellidae with com m onest forms in Antarctic and New Zealand waters . permesothyrid foramen; cardinalia consisting of soc ket All occupy soft substrates, som e exclusively (Gyrothyris, ridges, crural bases, and a cardinal process with trefoil Neothyris), while others {Magasella, Waltonia) are oppor­ posterior surface; loop axial to teloform . tunistic and may live as either cliff hangers or bo ttom dwellers (Richardson 1981b). G enera I ncluded : Anakinetica n.gen.: Tertiary and Re­ Brachiopods are also common on soft substrates of cent, Australia (Terebratella C um ingii Davidson 1852). the A ustralian shelf and are of interest for the fo llowing Australiarcula Elliott 1959: Cretaceous, Australia (Aus- reasons: traliarcula artesiana Elliott 1959). 1. W ith one exception, they are members of a subfam ily M agadina Thom son 1915: Tertiary, New Zealand (M aga- (M agadinae) unknown in m odern seas in any other are a; dina browni Thom son 1915). 2. The four m agadinids and one rhynchonellid described M agadinella Thom son 1915 Tertiary and Recent, A ustra­ are specific to the bryozoan sands that are continu ous lia (M agadinella Woodsiana Tate 1880). along southern Australia (Wass, Conolly & McIntyre Magas Sowerby 1816: Cretaceous Europe (M agas pum i- 1970); and lus Sowerby 1816). 3. They display a variety of adaptations of the ped icle Parakinetica n.gen.: Tertiary and Recent, Australia which is related to the occupation of a soft substr atum . (Parakinetica stewarti n.sp.). Pirothyris Thom son 1927: Recent, Australia (M agasella vercoi Blochmann 1910). SOURCES OF MATERIAL Rhizothyris Thomson 1915: Tertiary, New Zealand Living individuals of all species studied were collected (Bouchardia rhizoida H utton 1905). from Bass Strait during a cruise on Tangaroa, a res earch Tanakura H atai 1936: Tertiary, Japan (Tanakura tanakura vessel of the New Zealand O ceanographic Institute (now H atai 1936). Division of M arine Research, Departm ent of Scientif ic Only those genera with species available for study have and Industrial Research). Samples from this cruise are held been placed under the heading “Genera Included”. by the Division in W ellington (Q register) and by t he However, inclusion of the genera that Elliott and H atai M useum of Victoria, M elbourne. Locality data for th ese (1965) attributed to this subfamily in the Treatise is not and other stations sam pled in Bass Strait are liste d by W il­ disputed. son & Poore (in press) — registration num bers of M u seum of Victoria material are prefixed NMVBSS. Dried and C omments : The only living species (from four genera) preserved m aterial has also been studied from the c ollec­ described from this subfamily are benthic and confi ned tions of the M useums of Western Australia (W AM), So uth to carbonate sands. The position of individuals at the sur­ Australia (SAM), the Australian M useum (AM ) and the face of soft sediments is m aintained by the pedicle sys­ British M useum of Natural History (BMNH). tem which is distinctive in character in each genus . The sediments from which all species were collected Diagnostic features of genera are the areas used fo r at­ have been described in the publications of Wass, Co nolly tachm ent of the dorsal adjustor muscles and details of and M cIntyre (1970), M arshall and Davies (1978), Jo nes the beak—its length and curvature and whether deltidial and Davies (1983) and Quilty (1985). plates are fused or discrete and the beak ridges sh arp or 37 38 J. R. RICHARDSON rounded. No living species from the same genus co-e xist, C omments : The type species of M agadina is M. browni but sufficient Tertiary species have been collected to show from Waipara, New Zealand. In this and other New the characters that differentiate species. Three sp ecies in­ Zealand species attributed to M agadina, components of cluded in Anakinetica (from Recent seas, Miocene & the cardinalia are not fused together to form a solid plat­ Oligocene deposits) differ in shell outline, in deg ree of form , the cardinal process is not swollen, and a de ep hinge convexity of the valves, and in the shape and relative size trough separates the crural bases. Thomson noted th e of the area occupied by the cardinal platform . The differ­ difference between the two groups of species — “Car dinal ences are slight but consistent and are easily iden tifiable. process in primitive species (genotype) small but c onfined O ther fossil species attributed to Anakinetica display an to the um bonal end of the hinge-trough, in advanced spe­ incurved beak and heavy posterior thickening, and s econ­ cies (M cumingi) large and swollen com pletely filling the dary loss of the pedicle may be inferred from these hinge trough” (1927, p. 275). Growth stages of A. cumingi characters. described below indicate that the crural bases also con­ Some of the genera (Australiarcula, Rhizothyris, tribute to filling the hinge trough—they fuse media lly with Tanakura) described from fossil species are similar in each other and with the anterior surface of the car dinal character to Anakinetica and Parakinetica, i.e., with a process. solid cardinal platform without a hinge trough and with Anakinetica includes one living species and three Ter­ attachm ent areas of the dorsal adjustor muscles in the tiary species form erly included in M agadina—Terebratula posterior position indicating ratchet-like movement s of compta Sowerby 1845 (Oligocene-M iocene), Terebratella a free pedicle. Australiarcula artesiana was described from tenisoni Tenison-W oods 1865 (Oligocene-M iocene), and glauconitic sands of the Great A rtesian Basin (Elliott 1959, M agasella deform is Tate 1880 (Upper Eocene). In addi­ Parkin 1969), Tanakura tanakura from coarse-grained tion, collections m ade from Beaum aris, Victoria (U. M i­ sandstones in Japanese M iocene deposits, and num ero us ocene) and from the Jandakot Bores in W estern Austr alia species of Rhizothyris occur in greensands and bryozoan (Pleistocene) show that m embers of the genus were a com ­ calcarenites of the New Zealand Tertiary (Thom son 1915, m on com ponent of Australian shelf faunas during the Ter­ Allan 1960, Bowen & Campbell 1973). tiary. Characters that separate species are adult loop stage, The non-terrigenous character of the sediments oc­ configuration of the cardinal platform , and details of the cupied by members of the subfamily is noteworthy. A ll beak. living species have been collected from bryozoan sa nds Anakinetica cumingi (Davidson 1852) while m embers of fossil genera have been described from Fig. 1 chalks, calcarenites and greensands. It is not possible to define any ancestor/descendan t Terebratella (?) Cum ingii: Davidson 1852a, p. 78, pi. 14, relationships in different genera because all are s pecia­ figs 10-16. lised for benthic life in a particular type of sediment. Com­ Terebratella (?) Cumingii: Davidson 1852b, p. 368. parison with the subfam ily Bouchardiinae illustrate s this Terebratula (Bouchardia) Cumingii: Reeve 1861a, pi. 8, point. The latter family contains four genera, thre e (Ne- fig. 30. obouchardia, Bouchardia, Bouchardiella) specialised for Terebratula (Bouchardia) Cumingii: Reeve 1861b, p. 179. life in biogenic sands, one (M alleia) with characters as­ Terebratula (Bouchardia) fibula: Reeve 1861b, p. 180. sociated with a sedentary life style (Richardson 1973) and M agasella Cumingii: Dali 1870, p. 137. so it is possible to differentiate characters assoc iated with M agasella (?) cumingi: Davidson 1880, p. 18. life style from those that suggest com m on ancestry, e.g., M agasella Cumingi: Davidson 1886, pp. 97-99, pi. 17, figs the shape of the cardinal process and the absence o f crural 23-32. bases. The trefoil shape of the cardinal process of the M agasella cumingi: Verco & Blockmann 1910, p. 97. M agadinae is probably a familial character but cann ot be M agadina cumingi: Thom son 1915, p. 400, fig. 12. confirm ed as such in the absence of genera that occ upy M agadina cumingi: Thom son 1927, pp. 275-277. different substrates and follow a different life style. M agadina cumingi: Cooper 1973, p. 30, pi. 5, figs 39-42. M agadina cumingi: Richardson & W atson 1975a, pp. 381- Genus Anakinetica gen. nov. 382, fig. 1. M agadina cumingi: Richardson & W atson 1975b, pp. 379- E tymology : From the Greek ana (up) kineticos (moving).