Sous-embranchement (subphylum) des Rhynchonelliformea  
Classe des Rhynchonellata 
Ordre des Rhynchonellida 
Super-famille des Pugnacoidea 
Super-famille des Dimerelloidea 
Super-famille des Norelloidea 
Super-famille des Hemithiridoidea 

Genus Basiliolella d’Hondt, 1987
[Type species= Basiliolella ferox d’Hondt, 1987]
Small, subtriangular, smooth but for few, obscure marginal plicae; uniplication flattopped, pauci- dentate; beak ridges submesothyrid; foramen small, slightly auriculate. Median septum reduced to a ridge or low keel; distal ends of crura broad and truncated or serrated; crural bases thickened, increasingly swollen to medially coalescent.

Diagnosis from volume 4 of the
Treatise on Invertebrate Paleontology (2002)

Extant Species of Basiliolella
  • B. grayi (Woodward, 1855)
  • B. colurnus (Hedley, 1905)
  • Diagnosis

     FIGURES : Basiliolella

         Geographic distribution

    Basiliolella grayi  (Woodward, 1855)

    Type locality: "present unique shell was sent with other natural-history objects from the Feejee Islands by J. M'Gillivray, Esq., Naturalist to the Surveying Expedition under Capt. Denham of H.M.S. Herald" (Woodward, 1855, p. 444)
    Depth range: 160 - 600 m

    Basiliolella ferox d’Hondt, 1987, p. 39.

    Diagnose (Woodward, 1855)

    "Shell light horn-colour, dull, trigonal, depressed; sides rounded; front truncated; beak small, acute; valves smooth, obscurely marked by lines of growth, and strongly plaited near the margin with four central plaits and three or four on each side, the furrows obscurely striated; margins of the valves sinuated in front and strongly toothed; foramen minute, completely tubular. Long. 15, lat. 13, alt. 8 mill."

    Diagnose (d'Hondt, 1987)

    "Suture du bord antérieur découpée par des indentations triangulaires acérées."

    Basiliolella colurnus  (Hedley, 1905)

    Type locality: "111 fathoms east of Cape Byron, it was taken by Mr. Halligan and myself in 100 fathoms east of Wollongong. From this parcel the type was selected."
    Depth range: 181 - 457 m

    Hemithyris colurnus Hedley, 1905, p. 44.

    Diagnose (Hedley, 1905)

    Shell shallow, triangular-cordate, smooth except for faint" growth lines, glossy, translucent though solid, pale horn colour. Edges of valves broad and bevelled. The brachial valve has the beak incurved. Crural plates separate to the umbo, projecting, forked distally, furrowed along the upper surface. Teeth sockets sharply transversely gro- oved. There is no septum, but in old and thickened individuals a bilobed shelly mass appears in its place. The pedicle valve has the beak produced. The small oval foramen completed by the deltidial plates. Teeth strong projecting. In front the central third of the valve projects outward and upward into the mesial sinus of the corresponding valve; behind it is a broad shallow sinus.

    d'aprËs Bitner (2019)