Figure 1 - Stolleya ornatissima, (rk1135)
hemisperical fragment with radiating needles. Alemannia, Höver, senonensis Zone
Figure 2 - Stolleya ornatissima, (rk1135)
side view of aligned dichotriaenes (some broken). Alemannia, Höver, senonensis Zone
Figure 3 - Stolleya ornatissima, (rk1135)
aligned dichotriaenes and oxeas. Alemannia, Höver, senonensis Zone
Figure 4 - Stolleya ornatissima, (rk1135)
Detailed view of the cladomes of dichotriaene scleres. Alemannia, Höver, senonensis Zone
Figure 5 - Stolleya ornatissima, (rk1135)
Immature (plagio)triaenes, partially with lacking bifurcation of clads. Alemannia, Höver, senonensis Zone
Figure 6 - Stolleya ornatissima, (rk1135)
isolated dichotriaenes and oxeas. Alemannia, Höver, senonensis Zone
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Synonyms:
none
Occurence:
Höver, Lower Campanian (senonensis zone). Very rare.
Misburg, Upper Campanian. Very rare.
Oberg, Lower Campanian. Very rare.
Stolleya ornatissima was described by Schrammen (1899) as a new species from the Lower Campanian of Oberg.
Schrammen (1912) distinguished two further Stolleya species (S. microtulipa and S. florida)
on the basis of subtle differences of their dichotriaenes.
Stolleya ornatissima occurs in spherical to irregular lumpy shapes, with diameters typically in the range of 40 to 80 mm.
Distinct canal systems seem to be lacking. In the quarry, specimens are very inconspicuos and are only discovered when broken, showing their radial fibre structure. See Figure 1.
Etched specimens (Figures 2, 3 and 4) reveal the radial structure imparted to the sponge by numerous densely packed, subparallel oxeas and dichotriaenes.
Triaenes and oxeas are the only sclere types observed (Figure 6). Both types may reach and probably exeed 7 mm in length.
The oxeas are fusiform and generally straight, but may also be curved or sinuous. When well preserved, an axial canal can be observed, which exits at both ends of the oxea.
The triaenes are plagiotriaenes, mostly with bifurcated clads forming dichotriaenes.
Immature examples may lack bifurcation in one or more of their clads and may resemble simple plagiotriaenes or even protriaenes).
See Figure 5. An axial canal may be visible in (broken) rhabdomes.
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