The adapical termination of the mould is smoothly rounded, indicating closure of the earliest whorls by a transverse septum, probably one of several such septa of the type illustrated by Lindstrom (1884, pl.
True muscle attachment scars are also deeply placed in Asgardaspira, adapical of the spiral ridge and groove complex.
Groups of interambulacral plates were excised from three regions on the skeleton: adapical, ambital, and adoral.
= 2,26), with adapical sutures being significantly stronger than ambital or adoral sutures (P [less than] 0.05, Fisher PLSD).
Each ambulacrum and interambulacrum has an "adapical
" end (at the apical system) and an "adoral" end (at the peristome).
First teleoconch whorl sculptured by somewhat sinuous axial pliculae; 3 spiral cords arise during second whorl and a fourth, beneath the adapical
suture, during whorl three; sculpture of subsequent whorls comprising 4 (rarely five) spiral cords (not counting that level with abapical suture), these crossed by somewhat irregular, prosocline axial pliculae (30-40 on last adult whorl); cords with scale-like nodules where crossed by pliculae, those on uppermost (subsutural) cord frequently larger; intervals between cords slightly wider than cords themselves; cord intervals on last adult whorl occasionally with a weak intermediary cord.
20 axial pliculae; 3 spiral cords develop during second whorl (lowest level with abapical suture), and a fourth arising beneath adapical
suture near end of whorl; subsequent whorls with further cords arising through intercalation; penultimate whorl with 7-9 cords, sometimes alternating a little in strength, sometimes not; seventh cord usually peripheral; cords well defined, equal to or wider than their intervals.
56A, C): White to translucent white, strongly exsert; diameter 260280 um; apical beak scarcely evident; surface evidently smooth; terminal lip roundly angled between mid-whorl and adapical
Apical surface of teleoconch sculptured by close-set axial riblets, these becoming much weaker at periphery and scarcely evident at all on base except around and within umbilicus; base also with traces of spiral striation in some specimens; aperture suboval, somewhat obliquely descending outwards; outer lip of adult frequently thickened basally, but sometimes also retaining a membranous periostracal fringe; adapical
portion of outer lip often flattened; upper part of columella lip reflected; umbilicus of moderate width, not obscured to any appreciable degree by reflected columella lip.
Protoconch diameter 3.5-4.1 mm, initially somewhat smooth, but with distinct axial riblets developing along adapical
suture during first whorl, these extending to abapical suture on second whorl (Fig.
Spiral ridges thinner than axials in intervals, expanding on ribs to form angular nodules, ridges nearly equal in strength, adapical
row slightly the stronger, abapical one slightly weaker; first two whorls with two rows of nodules plus a third usually beginning to develop above suture, later whorls with three main rows of nodules, plus a weak ridge immediately below suture; last whorl with a shallow waist-like furrow at base of rostrum containing a thin ridge, strengthening and bearing angular nodules on dorsum; rostrum forming a moderate fasciole, which bears 3 ridges weakening anteriorly, the upper 2 with angular nodules.