In even the smallest known specimen of " Eusthenopteron foordi " ( at 29 mm ), the lepidotrichia cover all of the fins, which does not happen until after metamorphosis in genera like " Polyodon ".
12.
As a result of Lac�p�de's inadvertent double naming, " Polyodon spathula " became the preferred scientific name of American paddlefish, and " Squalus spathula " became the synonym as one of two names applied to the group.
13.
An example of occurrence of " T . tannensis " within a tiered phytocoenosis is in Central epiphytic associates include " Asplenium polyodon ", " Astelia solandri " and " Blechnum discolor " along with " T . tannensis ".
14.
The family Polyodontidae comprises five known taxa; three extinct taxa from western North America, and two extant taxa including the American paddlefish ( " Polyodon spathula " ) native to the Mississippi River Basin in the United States, and the critically endangered Chinese paddlefish ( " Psephurus glades " ) endemic to the Yangtze River Basin in China.
15.
There are six known species : four extinct species known only from fossil remains ( three from western North America, one from China ), and two extant species, including the American paddlefish ( " Polyodon spathula " ) which is native to the Mississippi River basin in the U . S . and the critically endangered Chinese paddlefish ( " Psephurus glades " ) which is endemic to the Yangtze River Basin in China.
16.
The teeth of " Harpymimus " differ from those of another basal ornithomimosaur, " Pelecanimimus polyodon ", in that they are restricted to the dentary, are cylindrical and separated by interdental plates, and number at least ten and perhaps eleven per side . " Pelecanimimus " possessed per side seventy-five dentary teeth in the lower jaw, as well as an additional thirty-seven teeth in the upper jaw ( maxilla and premaxilla ).
17.
The first ornithomimid dinosaur described in Europe, " Pelecanimimus polyodon ", shows some characters previously unknown in these dinosaurs which enhanced the knowledge on the evolution of the group, such as a high number of teeth . " Concavenator corcovatus " presents two unique features : very tall neural spines on the vertebrae near the hip, which look like a hump, and a structure on its forearm, which if homologous to quill knobs would push back the origin of feathers earlier in theropod evolution.
18.
""'Allognathosuchus " "'is an extinct genus of based on fossils that are difficult to distinguish from other Paleogene alligatorids . " A . heterodon " is from the Eocene-age Wasatch Formation of Wyoming, " A . wartheni " is from the Eocene-age Wildwood Formation ( also known as the " Wildwood alligatorid, " and possibly two species ), and " A . woutersi ", which may belong to " Diplocynodon " instead, is from the Early Eocene of Belgium . " A . polyodon ", " A . heterodon ", and " A . wartheni " span the Clarkforkian, Wasatchian, and Bridgerian North American Land Mammal Ages.
