Early Cretaceous Pipid Tadpoles from Israel (Amphibia: Anura)

Early Cretaceous fossil tadpoles from Isreal are referred to Shomronella jordanica gen. et sp. nov. and assigned to the frog family Pipidae. The fossils are well preserved, many bones are uncrushed, and a number of features of soft anatomy are preserved, including body outline, choroid cup of eye, thymus gland, cephalic blood vessels, and spinal nerves. The fossils are compared with the normal tables of development for living Xenopus laevis, and the majority correspond approximately to stage 57-59; a small specimen (the only one lacking both fore- and hindlimbs) appears to be at about stage 52-53 and the most mature specimen at about stage 60-61. Shomronella jordanica, although clearly pipid, has few derived character states in common with other pipid species, either fossil or Holocene, and in some respects seems to be the most primitive known member of the group. It shares some primitive character states with other Cretaceous pipids from Israel and some with a morphologically primitive living genus (Xenopus); outside of the Pipidae there are some resemblances to the extinct pipoid family Palaeobatrachidae. Shomronella jordanica is distinctive in the shape of its parasphenoid and cleithrum. These fossil tadpoles are of interest in demonstrating the extremely ancient development of the pipid tadpole and its midwater filter-feeding adaptation.