Trilobites and agnostids from the Goyder Formation (Cambrian Series 3, Guzhangian; Mindyallan), Amadeus Basin, central Australia Author Smith, Patrick M. Author Paterson, John R. Author Brock, Glenn A. text Zootaxa 2018 2018-03-19 4396 1 1 67 journal article 30484 10.11646/zootaxa.4396.1.1 918f2145-a708-460e-b19b-4f67e6c99b30 1175-5326 1202723 8EEBE6DE-0ECC-4B9C-AD14-01438291782B Biaverta Öpik, 1967 Type species. Biaverta biaverta Öpik, 1967 . Discussion. Öpik (1967) originally placed Biaverta Öpik, 1967 in the Menomoniidae Walcott, 1916 based on its concave preglabellar field, large, strongly convex palpebral and posterior areas, deep glabellar furrows that widen (exsag.) slightly adaxially, and anteriorly situated palpebral lobes. Bentley et al. (2009) suggested that Biaverta was better placed in the Nepeidae Whitehouse, 1939 rather than the Menomoniidae (Öpik 1967; Wang, et al. 1989 ). The characteristics used by Paterson (2005) to define the Nepeidae exclude Biaverta because it lacked a number of key features, including: distinctive palpebral lobes; prominent bifurcating eye ridges; and a preglabellar boss. However, Westrop & Adrain (2009) conducted a cladistic analysis, which revealed Biaverta as an ingroup member of the Nepeidae . This result was largely based on the shared deep lateral glabellar furrows, large, convex palpebral and posterior areas, and a posterior border furrow that is deep abaxially, but shallows at the steep downturn near the extremities of the posterolateral projections.