| Home> Cenozoic> Miocene>
 

List species

Tholospyris cortinisca (Haeckel, 1887)

Description - Add description

Tripospyris (Tripospyrantha) cortiniscus
Shell ovate, smooth, one and a third times as long as broad, with sharp ovate sagittal stricture and broad primary ring. Basal plate with two large cardinal pores only. Occipital plate with two pairs of very large pores; facial plate and lateral sides with numerous smaller irregular roundish pores. Apical horn small, conical, curved, half as long as the three basal feet, which are club shaped and three-edged, with thinner bases and half as long as the shell, strongly divergent.
Dimensions.-Shell 0.12 long, 0.09 broad; horn 0.03 long, feet 0.06 long.
Habitat.-Central Pacific, Station 266, depth 2750 fathoms.
Haeckel 1887
Tholospyris cortinisca
Description.—Sagittal ring subpolygonal; 46 to 75µ high: and 37 to 55µ wide; joined directly to front and back of lattice shell. Frontal spine short; vertical spine very short, projecting from lower third of sagittal ring; no apical spine, axial spine, or pairs of saggital-ring spines. Single connector bar projects vertically from apex of front of sagittal ring; primary-lateral bars joined to basal ring; no other connector bars. Basal ring oval, indented laterally and sagittally; 46 to 90µ wide; 28 to 54µ thick; joined directly to front and back of sagittal ring: encloses four basal pores. In some specimens, basal ring has thin median rib on outer surface. Three basal spines, 7 to 58µ long, project from basal ring. One of foregoing spines is short, simple frontal spine; other two basal spines are longer, irregularly silicate, and adjacent to primary-lateral bars. Lattice shell 78 to 124µ high; 62 to 147µ wide; surrounds apex of sagittal ring; does not extend below basal ring; perforated by subcircular, densely spaced lattice pores 2 to 25JA in diameter. Variable number of lattice bars joined to basal ring; none of them adjacent to primary-lateral hars. Four lattice bars joined to sagittal ring. One junction at base of apical connector bar; one junction between frontal spine and apical connector bar; two junctions between vertical spine and apical connector bar. In some specimens, these lattice bars have outer median rib, whereas other skeletons display pairs of tubercles at junctions of lattice bars and sagittal ring. Four pairs of sagittal-lattice pores are two to eight times larger than other lattice pores; no vertical, frontal, or sternal pores. Lattice shell smooth; single sulcate lattice spine projects from apex of lattice shell.
Remarks.—Representatives of Tholospyris cortinisca differ from those of Dendrospyris damaecornis and D. binapertonis Goll in having a lattice shell that projects above the apex of the sagittal ring and from those of T. kantiana and T. infericosta, n. sp., in having three basal spines. In skeletons of the type-species of Trissocyclidae, Liriospyris clathrata, the lattice shell does not surround the apex of the sagittal ring, and a sternal bar is present. The species included in the above synonymy are distinguished on the basis of variations of the shape of the basal spines and distribution of the lattice pores. I have not observed any systematic variation in these skeletal features.
Occurrence.—Representatives of Tholospyris cortinisca are in all but two of the samples above MSN 132P, 350-52 cm. (middle Miocene).
Hypotype.—USNM 650341, from core sample MSN 143P, 890-92 cm. (middle Pliocene).
Goll 1969


Description

 

Images

 

Synonyms

 

References

 

Distribution

 

Discussion / Comments

 

Web links