We describe the first known occurrence of a Devonian coelacanth specimen from the lower Famennian of the Holy Cross Mountains, Poland, with a conodont element preserved in its digestive tract. A small spiral and phosphatic coprolite (fossil excrement) containing numerous conodont elements and other unrecognized remains was also found in the same deposits. The coprolite is tentatively attributed to the coelacanth. Although it is unclear whether the Late Devonian coelacanth from Poland was an active predator or a scavenger, these finds provide the first direct evidence of feeding on conodont animals by early coelacanth fish, and one of the few evidences of feeding on these animals known to date. It also expands our knowledge about the diet and trophic relations between the Paleozoic marine animals in general.Electronic supplementary materialThe online version of this article (doi:10.1007/s00114-017-1455-7) contains supplementary material, which is available to authorized users.
The development of the upper end of the femur was determined from radiographic analysis of the hips in 191 children and a small series of cadaver specimens from young subjects, with special attention directed to the internal architecture. At birth, linearly arranged trabeculae are present but not visible on conventional radiographs. During the latter part of the first year, trabeculae are seen on conventional studies in an apparently random orientation. Although the principal medial and lateral groups of trabeculae can be shown on coronal slab sections before the end of the first year, they cannot usually be seen on conventional radiographs until 12 to 24 months. The trabecular pattern is well established by the fifth year, although the secondary lateral and linearly oriented trochanteric trabeculae are not easily seen before adolescence. The relevance of these findings in relation to diseases of the hip and upper femur is examined.
Soft tissue preservation is reported from Upper Devonian deposits of the Holy Cross Mountains, central Poland, for the first time. The preserved soft tissues are muscles associated with arthropod cuticle fragments. The muscles are phosphatized with variable states of preservation. Well-preserved specimens display the typical banding of striated muscles. Other muscle fragments are highly degraded and/or recrystallized such that their microstructure is barely visible. The phosphatized muscles and associated cuticle are fragmented, occur in patches and some are scattered on the bedding plane. Due to the state of preservation and the lack of diagnostic features, the cuticle identification is problematic; however, it may have belonged to a phyllocarid crustacean. Taphonomic features of the remains indicate that they do not represent fossilized fecal matter (coprolite) but may represent a regurgitate, but the hypothesis is difficult to test. Most probably they represent the leftover remains after arthropod or fish scavenging. The present study shows that soft tissues, which even earlier were manipulated by scavenger, may be preserved if only special microenvironmental conditions within and around the animal remains are established.
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