Extant vertebrates are divided into three major groups: hagfishes (Hyperotreti, myxinoids), lampreys (Hyperoartia, petromyzontids), and jawed vertebrates (Gnathostomata). The phylogenetic relationships among the groups and within the jawed vertebrates are controversial, for both morphological and molecular studies have rendered themselves to conflicting interpretations. Here, we use the sequenc...

The study include the description of fish assemblage in Al- Saffia reservation during period March 2006 to February 2007. Sixteen osteichthyes species were obtained, highest number 13 was recorded July and lowest 7 November January. largest individuals collected obtained (212) (124). Four formed 71.02% Alburnus mossulensis 20.64 % Liza abu19.62 Barbus luteus16.13 Carassius auratus 14.46 %. annu...

Well exposed Famennian, mainly carbonate rocks of the Bahram Formation in the vicinity of Bagher Abad village, Central Iran,yielded chondrichthyan teeth some sarcopterygii and actinopterygii teeth and fragments. Three different genera were recognizedamong the chondrichthyan teeth represented by: Phoebodus turnerae, Ph. spp., Deihim mansureae (M2, M3), Stethacanthus sp..Acanthodian and sarcopter...

The Rhipidistia (Osteichthyes, Crossopterygii) comprise three superfamilies of Paleozoic fossil fishes, the Holoptychoidea, Osteolepoidea and Rhizodontoidea. Of these the members of the Holoptychoidea (families Holoptychidae and Porolepidae) are by far the least well known, and consequently there exists a considerable gap in our knowledge of the evolution of the Rhipidistia as a whole. The aim ...

The tooth plates in the living Holocephalan, Chimaera phantasma were studied by various techniques. They consisted of osteodentin and hypermineralized pleromin (kosmin). The degree of mineralization on the latter was as much as in the enameloid of Chondrichthyes and Osteichthyes. Scanning electron microscope observation indicated that the pleromin consisted of large and granular crystals. X-ray...

well exposed famennian, mainly carbonate rocks of the bahram formation in the vicinity of bagher abad village, central iran,yielded chondrichthyan teeth some sarcopterygii and actinopterygii teeth and fragments. three different genera were recognizedamong the chondrichthyan teeth represented by: phoebodus turnerae, ph. spp., deihim mansureae (m2, m3), stethacanthus sp..acanthodian and sarcopter...

Hypoxia-inducible factor (HIF) is a crucial regulator of cellular and systemic responses to low oxygen levels. Here we firstly cloned three HIF-α isoforms from the basal branches of Osteichthyes and used computational tools to characterise the molecular change underlying the functional divergence of HIF-α isoforms in different lineages. Only the HIF-1α and HIF-2α in African lungfish and amphibi...