Pteropelta kielanae ( Hints, 1998 ) Hints & Eriksson, 2010

Hints, Olle & Eriksson, Mats E., 2010, Ordovician polychaeturid polychaetes: Taxonomy, distribution and palaeoecology, Acta Palaeontologica Polonica 55 (2), pp. 309-320 : 313

Pteropelta kielanae ( Hints, 1998) comb. nov.

Fig. 2A–C.

1966 “ Polychaetura ” sp. a; Kielan−Jaworowska 1966: 105–106, pl. 23: 1, 2.

1998 Polychaetura kielanae sp. nov.; Hints 1998:497–498, figs. 12H–L.

2000 Pteropelta kielanae (Hints) ; Hints 2000: pl. 2: 8.

Emended diagnosis.— Hints (1998: 498) diagnosed this species as differing from Polychaetura gracilis in having wider posterior maxillae (MI), a left MI with straight instead of incurved posterior margin and a longer inner wing. It differs from P. gracilis , P. huberti , and Pteropelta sp. A in having a right MI with sub−rectangular instead of triangular outline of the shank.

Remarks.— Hints (1998: fig. 12H) illustrated a fused right MII and MIV from this species in which the same feature as discussed above for Polychaetura gracilis can be observed, i.e., that the individual denticles of these anterior maxillae are weakly fused and their boundaries continue through the element providing a lamella−like appearance. Whether or not P. huberti and Pteropelta sp. A also have similar anterior maxillae is presently not known. If this proves to be a feature typical for all polychaeturids their supposedly close relationship to polychaetaspids and ramphoprionids ( Kielan−Jaworowska 1966) may need reconsideration.

Stratigraphic and geographic range.— Pteropelta kielanae is most common in the Haljala and Keila stages (Sandbian to basal Katian) of Estonia and NW Russia. Questionable finds derive from the Uhaku Stage (upper Darriwilian) of Estonia and Kukruse Stage (basal Sandbian) of south−eastern Sweden (MEE, unpublished data).