body parts, while the head is bent backwards (Miiller 1951) — as seen 

 in a specimen of Clupea sardinites (in Plate V, Fig. 1) or, 



(b) the water current bends the body in a direction opposite to 

 that normally occurring after death — that is downwards. An example 

 of this manner of preservation is seen in Idrissia carpathica — Plate V, 

 Fig. 2. 



Group 4. Detached heads of fossil Clupeidae are encountered (Wei- 

 ler 1929; Pauca 1934) and may be accounted for by the head breaking 

 off owing to a natural post-mortem body curvature. Detached heads 

 of Sternoptychidae have not so far been recorded. Their occurrence, 

 ascertained by the writer, cannot be explained by the same cause as in 

 the case of the Clupeidae, since the Sternoptychidae, which have a high 

 body, are not subject to post-mortem bending. Therefore, the correct 

 interpretation here is possibly that suggested by Hecker and Merklin 

 (1946). These authors suppose that the detached fish heads, present 

 among other fossil remains, may have sunk down to the sea-floor 

 (where they were preserved in the bottom deposits), while the hind 

 part of the body trunk was bitten off by a pursuing predator. 



Group 5. Headless bodies are seldom encountered in fossil material. 

 The explanation here may perhaps be that the body was bitten off 

 by a predatory fish, since it bears no signs of deformation or decay. 



The biostratonomic analysis of the fish remains examined indicates 

 that the Jaslo shales sedimented in a calm sea. Lack of significant body 

 deformations in most of the collected fish remains, and the preservation 

 in situ of some scales of Clupeidae, lend support to this supposition. 

 On the other hand, however, even the rare occurrence of strongly 

 deformed fish remains suggests the action of some local bottom currents. 

 At the same time the abundance of fishes with luminous organs ex- 

 cludes a shallow-sea basin, hence also bottom water-movements due 

 to the action of waves. Therefore, it seems reasonable enough to infer 

 that the stronger deformations of skeletons are caused by bottom 

 currents. These currents would, likewise, be responsible for the absence 

 of scales in the proximity of fish skeletons, while the preservation of 

 the pigment in the pigment cup of the various photophores within the 

 skin, together with lack of disruption of the head body bones, certainly 

 indicate an early cessation of decay. 



Interesting, too, is the occurrence within the Jaslo shales of land 

 plant remains, such as laurel leaves. These leaves must have been 

 transported by surface currents. Fairly large fragments of sea-weeds 

 are also sporadically encountered. 



42 



