Exceptionally Rare Lower Cretaceous Amphibian

Positive Negative Fossil Pair

Liaoxitriton zhongjiani

Class Amphibia, Superorder Batrachia, Order CaudataUrodela

Geologic Time: Lower Cretaceous, (~125 m.y.a.)

Size: 110 mm long (tip of skull to tip of tail along backbone). Matrix: 296 mm by 60 mm

Fossil Site: Huludao City, Jiufotang Formation, Liaoning Province of China

Lower Cretaceous Amphibian fossilDescription: This is a fine positive/negative pair of a rarely seen amphibian; a salamander known as Liaoxitriton zhongjiani. It is placed here in the Reptile section of the store as amphibians are almost never offered. The species takes its generic name from Liaoxi, the general region from which the specimen comes, while the specific name is for the researcher who first discovered this specimen. The detail is incredible; even more remains to be uncovered (see some of the bones of the forearm). Even a 20 mm partial tail of another unknown vertebrate is present. Phyletogentic analysis of the Urodeles shows that Asia is the origin of the clade, leading to the hypothesis that the basal salamanders radiated from the region. Some salamanders demonstrate neoteny, or the capability of reproducing while in what is apparently the larval state. Note the soft tissue outlines preserved, and what appears to be gill structures, a telltale that this is not a larval form but a neotenic example. Neoteny is not all that uncommon among modern-day salamanders (some 40 species in 9 different families demonstrate this strategy), with the Mexican Salamander or Axolotl being a prime example. This means that it retains its gills and fins, and it doesn't develop the protruding eyes, eyelids and characteristics of other adult salamanders. It grows much larger than a normal larval salamander, and it reaches sexual maturity in this larval stage. The independent occurrence of neoteny in both Mesozoic and recent groups of salamanders makes parallel evolution of numerous morphological features an enduring feature of their history. An example such as this of the first salamander to be discovered from the Mesozoic in the east Asian region would make a fine addition to any public or private collection.

click fossil pictures to enlarge

l Fossil Mall Home l Fossils Science Section l

l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l