We describe in detail three braincases of the ankylosaur Bissektipelta archibaldi from the Late Cretaceous (Turonian) of Uzbekistan with the aid of computed tomography, segmentation, and 3D modeling. Bissektipelta archibaldi is confirmed as a valid taxon and attributed to Ankylosaurinae based on the results of a phylogenetic analysis. The topographic relationships between the elements forming the braincase are determined using a newly referred specimen with preserved sutures, which is an exceedingly rare condition for ankylosaurs. The mesethmoid appears to be a separate ossification in the newly referred specimen ZIN PH 281/16. We revise and discuss features of the neurocranial osteology in Ankylosauria and propose new diagnostic characters for a number of its subclades. We present a 3D model of the braincase vasculature of Bissektipelta and comment on vascular patterns of armored dinosaurs. A complex vascular network piercing the skull roof and the wall of the braincase is reported for ankylosaurs for the first time. We imply the presence of a lepidosaur-like dorsal head vein and the venous parietal sinus in the adductor cavity of Bissektipelta. We suggest that the presence of the dorsal head vein in dinosaurs is a plesiomorphic diapsid trait, and extant archosaur groups independently lost the vessel. A study of two complete endocranial casts of Bissektipelta allowed us to compare endocranial anatomy within Ankylosauria and infer an extremely developed sense of smell, a keen sense of hearing at lower frequencies (100–3000 Hz), and the presence of physiological mechanisms for precise temperature control of neurosensory tissues at least in derived ankylosaurids.

The measurements of scapula, pelvis, humerus, ulna, radius, tibia, femur, and the first three vertebrae of the adult wild cat Felis silvestris Schreber, 1777 from Bulgaria were used in this study. Considerable di(Terences between the sexes were revealed at three levels of significance in most of the sizes of scapula, pelvis, and vertebrae. The males were bigger than the females. No significant differences were found in the limb bones, except in the length of the humerus. Widening of the female pelvis was not observed. The variability of the skeletal parts examined was found to be comparatively low for most of them.

No abstract

The population status of bleak (Alburnus alburnut (L.) in sand-pit lake Chepintsi near Sofia by using some biological factors as growth rate, condition and fecundity was investigated. The maximum age, length and body mass of bleak were 3 years, 12.7 mm and 20 g, respectively.The first, second and third age group were 5.77%, 63.46%, 30.77% respectively. The linear and body mass growth rate were described by the equations: SL=1.3487+2.6601R (r=0.88); W=0.1499L 1.8499 (r=0.95), respectively. The condition coefficient of bleak (k) was the lower than that for other populations from different water bodies. Also the populations from different water basins were compared by the body mass at the same length. Fecundity was 7 168 eggs, the average was 1 707 -12 284 eggs. The fecundity-length and fecundity-weight relationship were described by the equations: F=387.32L+4365.7 (r = 0.46); F=1368.4W-3151.9 (r = 0.59) respectively.

S. 1992. Craniometrical sex determination of wild cat Felis silvestris in Bulgaria. Acta theriol. 37: 381 -396.Analyses were made of 118 skull measurements of adult wild cats Felis silvestris Schreber, 1777 from Bulgaria, taken on 24 males, 20 females, and 10 animals whose sex was not known in advance. Group (cluster) analysis of cases, factor analysis, and stepvise discriminant analysis were adapted. The cluster analysis of cases indicated a high level of sex mixture (up to 40%), which suggested the importance of the outliers in the data. Six keys to sexual dimorphism, of very high statistical significance were produced, through the stepvise discriminant analysis. They included from 9 down to 1 variables each, which provided from 100% down to 93.8% of correct sex classification of wild cat skulls.