CALLOPORIDAE NORMAN, 1903

Ostrovsky, Andrew N. & Taylor, Paul D., 2005, Brood chambers constructed from spines in fossil and Recent cheilostome bryozoans, Zoological Journal of the Linnean Society 144 (3), pp. 317-361 : 322-323

publication ID

https://doi.org/ 10.1111/j.1096-3642.2005.00179.x

DOI

https://doi.org/10.5281/zenodo.10545381

persistent identifier

https://treatment.plazi.org/id/6F0C243F-FF87-256C-FC26-66440223F896

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scientific name

CALLOPORIDAE NORMAN, 1903
status

 

FAMILY CALLOPORIDAE NORMAN, 1903 View in CoL

Remarks: Spinose ovicells were first described by Ostrovsky & Taylor (2004) in three Cretaceous calloporid genera. Here we present a more detailed description of the structure of their ovicells.

GENUS DISTELOPORA LANG, 1915 DISTELOPORA BIPILATA LANG, 1915

( FIGS 3A- D View Figure 3 , 21C View Figure 21 , 24I, L View Figure 24 )

Material: NHM D21876, D21879 View Materials -21883, D23019, Cretaceous, Lower Cenomanian, 10 ft (3.05 m) from the base of the Chalk Marl, Cambridge, England, F. Möckler Collection. NHM BZ4958 , Lower Cenomanian (? carcitanense Subzone), Porcellaneous Beds (= Chalk Marl), Barrington Chalk Pit, Cambridgeshire, England, A. N. Ostrovsky & P. D. Taylor Collection .

Description: Non-brooding autozooids (i.e. those that have no brood chamber on their proximal gymnocyst) possess 6–8 mural spine bases that indent the mural rim. These are usually paired, with the most proximal pair having the largest diameter and the distalmost pair (the oral spine bases) the smallest. The proximal part of the mural rim is usually devoid of spines ( Fig. 3A View Figure 3 ).

Brooding autozooids positioned distally of maternal (egg-producing) zooids usually have six, sometimes seven, mural spine bases plus an additional 5–10 (usually 6–7) spines that constructed the ovicell. As with the mural spines, only the bases of the ovicell spines are preserved, the spines themselves always being broken off at their basal articulations and lost in these fossils. Ovicell spine bases are aligned in a distally convex arch on the proximal gymnocyst of the distal (brooding) autozooid ( Figs 3A- D View Figure 3 , 24I, L View Figure 24 ). This arch is normally gently curved ( Figs 3A, C, D View Figure 3 , 24I View Figure 24 ), but is occasionally more convex ( Fig. 3B View Figure 3 , left ovicell), and a near semicircle of spine bases was found in one example ( Fig. 3B View Figure 3 , right ovicell, 24 L). As a rule, the median ovicell spine bases are adjacent to the proximal edge of the mural rim of the distal zooid, and may slightly indent it ( Fig. 3D View Figure 3 ). However, they can be also be positioned further from the mural rim ( Fig. 3C View Figure 3 ). The outermost spine bases are always well-separated from the distal edge of the maternal zooid. The distance between adjacent ovicell spine bases is equal to or greater than their diameters. They have either approximately the same diameter as the most distal oral spines or are smaller. The floor of the ovicell, formed by the proximal gymnocyst of the distal zooid, is slightly concave.

DISTELOPORA LANGI OSTROVSKY & TAYLOR, 2004 View in CoL

( FIGS 4A View Figure 4 , 21C View Figure 21 , 24I View Figure 24 )

Material: NHM D21873-21875, D21878, D23059, D23111, BZ4961 , BZ4962 , Cretaceous , Lower Cenomanian, 10 ft (3.05 m) from the base of the Chalk Marl, Cambridge, England, F. Möckler Collection .

Description: Non-brooding autozooids possess 9–11 (up to 16) mural spine bases, including usually four oral mural spines, though as many as six can be present. Proximal spine bases are typically slightly larger than distal spine bases. However, this character varies, and the largest spine bases can be any except for the most distal.

There are 10–12 mural spines in brooding (ooeciumbearing) zooids. Ovicell roofs were constructed of 7–8 spines borne on the proximal gymnocyst of the distal zooid ( Figs 4A View Figure 4 , 21C View Figure 21 , 24I View Figure 24 ). The bases of these articulated spines typically have the same diameter as distal oral spines but can be somewhat smaller or larger. They are arranged in a gently curved, distally convex arch. The median spines are normally adjacent to the proximal edge of the mural rim of the distal zooid ( Fig. 4A View Figure 4 ) but are sometimes separated from it by a narrow strip of gymnocyst. The outermost spine bases are always located far from the distal edge of the maternal zooid, and the distance between neighbouring ovicell spine bases is equal to or smaller than their diameter. The ovicell floor is slightly concave.

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Calloporidae

Loc

CALLOPORIDAE NORMAN, 1903

Ostrovsky, Andrew N. & Taylor, Paul D. 2005
2005
Loc

DISTELOPORA LANGI OSTROVSKY & TAYLOR, 2004

Ostrovsky & Taylor 2004
2004
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