Apparatus of the conodont Scolopodus striatus Pander, 1856 and re-evaluation of Panders species of Scolopodus

The Lower Ordovician conodont Scolopodus striatus Pander, 1856 (= Scolopodus rex Lindström, 1955) has an apparatus composed of five element morphotypes: acontiodiform, subrounded, compressed paltodiform, paltodiform, and scandodiform. The identification of the morphotypes is based on the general asymmetry of elements and shape of their bases. The elements are variable within each morphological group and form a continuous transition series generally reflected in differences in the depth of the basal cavity, height and degree of lateral compression of the base. The new collection from the localities near St. Petersburg, the type area of the first investigations on conodonts by Christian Pander in 1856, was examined and species of Scolopodus named by him are revised. All Pander’s species with the exception of the type species Scolopodus sublaevis are identified as a single species of Scolopodus that was named 99 years later as Scolopodus rex. The S. sublaevis sensu formae was not recognised in collections studied and its validity is questionable. S. striatus is the most easily recognisable among Pander’s species of Scolopodus and is here proposed to be a senior synonym of S. rex.