cyclostomatas造句

• The only vertebrates lacking a spleen are the lampreys and hagfishes ( the Cyclostomata ).
• Phylogenetic research in 1998 and 1999 supported the idea that the hagfish and the lampreys form a natural group, the Cyclostomata, that is a sister group of the Gnathostomata.
• The argument is that if the Cyclostomata are indeed monophyletic, Vertebrata would return to its old content ( Gnathostomata + Cyclostomata ) and the name Craniata, being superfluous, would become a junior synonym.
• The argument is that if the Cyclostomata are indeed monophyletic, Vertebrata would return to its old content ( Gnathostomata + Cyclostomata ) and the name Craniata, being superfluous, would become a junior synonym.
• The two genes are believed to result from a gene duplication event; the ancestral gene is estimated to be about 500 million years old and is found in cyclostomata ( modern members of the Agnatha ).
• Overall, the vertebrate fauna of the national park is represented of one species of cyclostomata, 20 species of fishes, 12 species of amphibians, 7 species of reptiles, 141 species of birds, 52 species of mammals.
• However, the validity of the taxon " Craniata " was recently examined by Delarbre et al . ( 2002 ) using mtDNA sequence data, concluding the Myxini are more closely related to Hyperoartia than to Gnathostomata  i . e ., that modern jawless fishes form a clade called Cyclostomata.