Hipponicharionidae Sylvester−Bradley, 1961

Álvarez, María Eugenia Dies, Gozalo, Rodolfo, Cederström, Peter & Ahlberg, Per, 2008, Bradoriid arthropods from the lower-middle Cambrian of Scania, Sweden, Acta Palaeontologica Polonica 53 (4), pp. 647-656 : 650-652

Family Hipponicharionidae Sylvester−Bradley, 1961 Genus Hipponicharion Matthew, 1886

Type species: Hipponicharion eos Matthew, 1886 from the lower Cambrian Hanford Brook Formation, Protolenus elegans Zone , in New Brunswick, Canada; by monotypy.

Remarks.—The most recent appraisal of the genus is by Siveter and Williams (1997), who also examined the type material of the type species. Their diagnosis of Hipponicharion is followed here. We also follow Siveter and Williams (1997) in considering H. cavatum Matthew, 1894 and H. minus Matthew, 1894 as junior synonyms of H. eos .

Hinz−Schallreuter (1993) and Gozalo and Hinz−Schallreuter (2002) described four other species from lower and?middle Cambrian strata in Morocco, Germany, and Spain. The oldest of them, H. elicki Gozalo and Hinz−Schallreuter, 2002 from the upper Zwethau Formation of the Torgau−Doberlug Syncline, Germany, has relatively short anterior and posterior lobes and a weak anterodorsal node. In these respects it is similar to the genus Bicarinella Rode, Lieberman, and Rowell, 2003 from the lower Cambrian of the Pensacola Mountains, East Antarctica. The general morphology of the lobes is, however, more in accordance with Hipponicharion .

The genus Wimanicharion Hinz−Schallreuter, 1993 is closely similar to the genus Hipponicharion and they differ mainly by the presence or lack of a connection between the anterior and the posterior lobe (see Hinz−Schallreuter 1993; Siveter et al. 1994; Siveter and Williams 1997). The material studied herein has a ventral gap between the two lobes ( Fig. 3C 3), suggesting that it belongs to Hipponicharion .

Neokunmingella Zhang, 1974 is another genus similar to Hipponicharion , but it differs from the latter in having confluent anterior and lateral lobes ( Williams and Siveter 1998; Hou et al. 2002).

Stratigraphic and geographic distribution.— Protolenus elegans Zone (Branchian Series) of New Brunswick, Canada ( Siveter and Williams 1997). Protolenid−strenuellid Zone (Comley Series) of England ( Williams and Siveter, 1998).? Sectigena Zone (Banian Stage; lower Cambrian) and? Ornamentaspis frequens Zone (middle Agdzian Stage; middle Cambrian) of Morocco ( Hinz−Schallreuter 1993; Gozalo and Hinz−Schallreuter 2002). Ovetian Stage (lower Cambrian) of Germany ( Elicki 1994; Gozalo and Hinz−Schallreuter 2002). Upper Marianian and lower Bilbilian Stage (lower Cambrian) of Spain ( Gozalo and Hinz−Schallreuter 2002; Gozalo et al. 2004). Uppermost Bilbilian Stage of Sardinia ( Elicki and Pillola 2004). Eccaparadoxides insularis Zone (middle Cambrian) of Poland ( Bednarczyk 1984) and Ptychagnostus praecurrens Zone (= Eccaparadoxides pinus Zone ; middle Cambrian) of Närke, south−central Sweden ( Streng et al. 2008).? Acadoparadoxides oelandicus Superzone (middle Cambrian) of Scania, southern Sweden ( Axheimer and Ahlberg 2003; herein).