Cyclurus macrocephalus REUSS , 1844

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 : 150-151

Cyclurus macrocephalus REUSS, 1844

D e s c r i p t i o n: Cyclurus scales ( Text-fig. 2 ) are typical elasmoid ones, “amioid type ” sensu Schultze (1966). The general shape is oblong to oval, with a more roundish posterior edge. The circuli are arranged in parallel rows. The concentric, diffuse or “untidy” arrangement is typical for the nucleus area. The nucleus is shifted to the posterior part of the scale. Annuli are visible in some specimens (see arrow at the Text-fig. 2a ). Variability of the scales is shown in Text-fig. 2 . Scales from the postanal lateral part of the body are especially well distinguishable for their elongated shape and fuzzy anterior edge ( Text-figs 2 e-g). The lateral line scales have a well developed canal for the sensory line ( Text-fig. 2i ).

Scales preserved in situ at the surface of the body are relatively common (e.g. Laube, 1901: taf. 1, fig. 2).

R e m a r k s: The scale of this species was figured by Grande et Bemis (1998: page 309, fig. 201). The same authors also noted the presence of eight scale rows above the lateral line, and seven below it.

The scales are very similar to the recent species Amia calva LINNAEUS, 1766 . The detail description with large discussion on the morphology and development of the scales in the A. calva was published by Grande et Bemis (1998), with summarization of previous works by other authors.

The presence of the amiid fish Cyclurus macrocephalus in the Kučlín was recognized by Reuss (1844) and later was discussed by von Meyer (1848, 1851). Laube (1901) placed the species in the genera Amia and definitive taxonomical identification to the genus Cyclurus has been provided by

Gaudant (1987). Additional osteological information was published by Gaudant (2008).

The remains of the species (including scales) were also recognized at the Roudníky (Gaudant in Bellon et al. 1998;

Přikryl, personal observation) and Kostomlaty ( Obrhelová et Obrhel, 1987; Böhme, 2007) localities in the České středohoří Mts.

Esociformes

Figures

Text-fig. 2. Cyclurus macrocephalus, scales. a-i – isolated scales: a – specimen IGP 2011/14; b – specimen IGP 2011/22, scale 2; c – specimen IGP 2011/18, scale 2; d – specimen NMP Pc 2868; e – specimen IGP 2011/17; f – specimen NMP Pc 2867; g – specimen IGP 2011/18, scale 3; h – specimen IGP 2011/16; i – specimen IGP 2011/18, scale 1. e-g – scales from the postanal area of the body; i – scale from the lateral line. Head should be in the left. Scale bars represent 1 mm.