The Echinoid Directory

Ortholophus Duncan, 1887, p. 413

[=Brochopleurus Fourtau, 1920, p. 25, type species Temnechinus stellatus Duncan & Sladen, 1886; =Irenechinus Fell, 1964, p. 211, type species Irenechinus hentyi Fell, 1964 [=Coptechinus pulchellus Bittner, 1892] ]

Diagnostic Features
  • Test low with rounded ambitus.
  • Apical disc small; plating dicyclic with square-ended ocular plates (not preserved in type species).
  • Ambulacra relatively wide, straight; pore-pairs uniserial; plating in triads with echinid-style plate compounding.
  • Single primary tubercle to each compound ambulacral plate, situated close to the zone of pore-pairs. Small secondary tubercle on perradial side, plus scattered miliaries.
  • Interambulacral plates a little wider than tall, with a single central primary tubercle plus scattered secondary tubercles. Base of primary tubercle with radial pits and ridges.
  • Primary tubercles imperforate and weakly crenulate.
  • Peristome small; buccal notches more or less absent.
  • Auricles of perignathic girdle fused perradially
  • Spines unknown.
Distribution
Upper Oligocene to Miocene, Pakistan, Australia, New Zealand, possibly Egypt.
Name gender masculine
Type
Temnechinus lineatus Duncan, 1877, p. 413, by monotypy. Holotype NHM E75600 (ex. Geological Society of London collections)
Species Included
  • O. lineatus Duncan, 1877; Upper Miocene, South Australia.
  • O. pulchellus (Bittner, 1892); Lower Miocene, South Australia.
  • O. venustus Philip, 1969; Lower Miocene, South Australia.
  • O. woodsi (Laube, 1869); Upper Oligocene, Lower Miocene, South Australia.
  • O. minor (Fell, 1964); Oligo-Miocene, New Zealand.
  • O. stellatus (Duncan & Sladen, 1886); Miocene, Pakistan.
  • O. gajensis (Duncan & Sladen, 1886); Miocene, Pakistan.
  • ?O. fallax (Lambert, in Lambert & Thiery, 1921); Miocene, Egypt.
Classification and/or Status
Euechinoidea; Camarodonta; Temnopleuridea; Trigonocidaridae.
Remarks

O. morganensis Philip, 1969; Middle Miocene, South Australia = Temnotrema.

Duncan, P.M. 1887. A Revision of the Echinoidea from the Australian Tertiaries. Quarterly Journal of the Geological Society of London 43: 413.

Philip, G. M. 1969. The Tertiary echinoids of South-Eastern Australia IV. Camarodonta (2). Royal Society of Victoria Proceedings 82, 233-275, pls 3-16.