|
Aulosoma radiciformis Phillips 1835
Aulosoma radiciformis is a common species, both in the Upper and Lower Campanian.
The general shape of Aulosoma radiciformis is cylindrical, more or less modified by ring-like bulges or rounded to acute tubercles. The surface of the species is relatively smooth, but on close inspection a network of fine, anastomosed furrows may be visible. In unetched specimens, the small inhalent pores are generally invisible to the naked eye. Aulosoma radiciformis has a deep central paragaster. The apex with the osculum may be rounded or conical, and sometimes the top part of the sponge is tapering. |
|
This picture of Aulosoma radiciformis shows an example with a more conical apex. Note that in many cases the sponges show a curved growth. This is probably a compensation for gradual tilting of the sponge on an unstable substrate. |
|
The specimen of Aulosoma radiciformis shown in this picture shows another extreme habit of Aulosoma radiciformis, with a very slender top and narrow paragaster opening. |
|
Some individuals of Aulosoma radiciformis show pronounced circular bulges.
|
|
Individuals with many tubercles resemble Stachyspongia of the Turonian, but the identity has not been proven yet. Tuberculated forms have been called Aulosoma radiciformis var. nodosus by Schrammen (1910, 1924)
|
|
Aulosoma radiciformis commonly shows a short stalk, which may have several strong, lateral roots.
|
|
A split specimen of Aulosoma radiciformis, showing deep paragaster, epirhysal and aporhysal canals penetrating the sponge wall, and exhalent pores (postica) discharging into the paragastral cavity. Notice that the postica are aligned horizontally, reflecting growth stages. Notice also that the aporhyses dip outward, while the epirhyses are subhorizontal or dip inward. |
|
Etched specimen of Aulosoma radiciformis, revealing longitudinally aligned inhalent pores. |
|
Photomicrograph of etched specimen of Aulosoma radiciformis, showing dense rhizoclone skeleton around an epirhysal canal. |
|
Photomicrographs of rhizoclones of Aulosoma radiciformis. Notice relatively small size and occurrence of conical thorns. |