Properca prisca (AGASSIZ, 1834)

Přikryl, Tomáš, 2011, Lepidological Review On The Fish Fauna Of The Kučlín Locality (Upper Eocene, Czech Republic), Acta Musei Nationalis Pragae Series B 67 (3 - 4), pp. 149-156 : 154

Properca prisca (AGASSIZ, 1834)

D e s c r i p t i o n: This species has scales of two types: cycloid and ctenoid ones ( Text-fig. 4 ). The major part of the body is covered by the ctenoid scales. The nucleus is antero-posteriorly elongated and is placed in the midline of the scale. Fine circuli are developed around the nucleus and are sectioned by radii in the cranial part of the scale.

Radii are present in relative high number (up to 13).

At the caudal part of the scale, there is a developed ctenoid field. Ctenii are arranged in one or several rows.

If more than one row is developed, ctenii from the vicinal rows alternate. Younger scales have fewer ctenii rows. The ctenii are short, tapered and sharp.

Cycloid scales are developed at the extremities of the fish body (e.g. in the caudal penducle, or at the dorsal edge of body – see Text-figs 4k, l ). Variability of the scales is shown in the Text-fig. 4 . Variability dependent on the place of origin is shown in the Text-figs 4 k-o.

Lateral line scales have large and elongated openings for the sensory canal in the middle part of nucleus ( Text-fig. 4p ).

Reconstruction of the position of the lateral line is showed in the Text-fig. 4q (based on the specimen NMP Pc 68).

R e m a r k s: The description of the scales is generally the same as was described by Obrhelová (1971, 1976), who also included specimen no. NMP Pc 2869 (Obrhelová,

1971: taf. IV, fig. 6) to the morphotype. The same specimen was obviously used as a pattern for the reconstruction in fig. 7c (Obrhelová, 1971: page 383). Micklich (1990) show-

ed affinity of this specimen rather to the moronids (see below).

The species was traditionally classified as a percid

(Laube, 1901). Obrhelová (1971) erected new genus Bilinia and supposed its relations to serranid, but revision of the original material suggests its affinity to the percichthyid fishes ( Micklich, 1988). Gaudant (2000) synonymized the

B. uraschista with species Properca prisca .

The fossil of Properca was already described (without preserved scaly covering) from the Kundratice locality in the České středohoří Mts. area (as B. bispinella by Obrhelová, 1976).

Perciformes

Moronidae sensu JOHNSON, 1984

Morone MITCHILL, 1814

Morone sp.

D e s c r i p t i o n: The species have typical large, subsquarish ctenoid scales ( Text-fig. 5). At the posterior part of the scale, there is developed a triangular ctenoid field. The nucleus is relatively large and is situated in the middle or posterior part of the scale. The ctenii are well developed, and are arranged fan-like in several rows. Ctenii from the vicinal rows create columns (see detail in the Text-fig. 5e). Separate ctenii are long and blunt. In the anterior part of the scale, there are developed numerous radii (up to 15). In the middle part of the lateral line scale, a large canal is developed ( Text-fig. 5c).

R e m a r k s: The scales of this type are clearly distinguishable and different from all previous taxa, and they are generally similar to the recent representatives of the family

Moronidae (see Text-figs 5g, h).

Although, we lack information about running of the lateral line scale or scale formula, the detail scale morphology was described in several publications.

Micklich (1990) published his interpretation of the specimen NMP Pc 2869 (Kuč. 80), which was originally classified as B. uraschista by Obrhelová (1971: fig. 7c; taf. IV, fig. 6). Other information, based also on the lepidological analysis and new material, was provided by Micklich et Böhme (1997), and all conclusions suggest pertinence of these fossils to the moronids. New discoveries of almost complete specimens with preserved scales were studied by Přikryl (2008), and he also classified the remains to the genus Morone .

Figures

Text-fig. 4. Properca prisca, scales. a – specimen IGP 2011/6b, scale 1; b – specimen IGP 2011/6b, scale 2, c – specimen IGP 2011/6b, scale 3; d – specimen IGP 2011/4a; e – specimen IGP 2011/7; f – specimen IGP 2011/1; g – specimen IGP 2011/8, scale 1; h – specimen IGP 2011/8, scale 3; i – specimen IGP 2011/8, scale 2; j – specimen IGP 2011/5a, scale 1; k – specimen IGP 2011/2a; l – specimen IGP 2011/3a; m – specimen IGP 2011/6b, group of scales; n – specimen IGP 2011/5a, group of scales; o – specimen IGP 2011/8, group of scales; p – specimen IGP 2011/7, lateral line scale; q – reconstruction of the running of the lateral line according to the NMP Pc 68; r-s – reconstruction of the scales according to Obrhelová (1976); t-z – reconstruction of the scales according to Obrhelová (1971). Head should be in the left. Scale bars represent 0.5 mm.