Monday, October 12, 2015

October unleashed. Guidraco

The describers of Guidraco classed‭ ‬it‭ ‬within the Pteranodontoidea‭ (‬the group defined by the type genus Pteranodon‭)‬,‭ ‬however they also found that its closest known relative was Ludodactylus which is actually a member of the Ornithocheiridae‭ (‬another group defined by the type genus Ornithocheirus‭)‬.‭ ‬These two groups of pterosaurs are closely related to one another,‭ ‬although the‭ ‬exact relationship of these groups can vary depending upon the author.
       The main context here however is the similarity to Ludodactylus,‭ ‬a pterosaur that at the time of description is only known from South America,‭ ‬specifically Brazil.‭ ‬This similarity if not a case of convergent evolution is taken as being evidence of a faunal interchange between the continents during the early Cretaceous.‭ ‬It should be remembered that the continents were in a quite different arrangement to what they are today with what is now the Atlantic Ocean being much narrower.‭ ‬As flying reptiles,‭ ‬pterosaurs‭ (‬particularly piscivorous ones‭) ‬could easily follow coastlines to reach into new continents.
       Guidraco is thought to have been a piscivore‭ (‬an eater of fish‭) ‬because of the arrangement of the anterior‭ (‬forward‭) ‬teeth that are both elongated and angled to point forwards rather than just up and down.‭ ‬This arrangement creates a large catch area of needle like teeth that significantly increases the chance of this pterosaur to catch and hold onto slippery prey like fish.‭ ‬These anterior teeth also have vertical ridges on the back while the teeth at the rear of the mouth are smooth.
       Guidraco also has a crest that rises up from the back of the skull similar to world famous Pteranodon,‭ ‬but it lacks the semi-circular‭ ‘‬keel crests‭’ ‬on the tips of the jaws that are present in other ornithocheirid genera such as Ornithocheirus.‭ ‬Instead the closest match is to the aforementioned Ludodactylus which seems to have had a similar head crest to Guidraco while also lacking the keel crests.‭ ‬Although pterosaur crests have often been described as flying aids for such things as steering,‭ ‬the incredible variety amongst different genera is more indicative of the crests being used for display purposes.‭ ‬This could not only be for the purpose of attracting a mate,‭ ‬but for recognising others of their own kinds during a time when the skies would have been full of multiple kinds of pterosaurs.
       The name Guidraco is a combination of the Chinese‭ ‘‬Gui‭’ ‬which means‭ ‘‬malicious ghost‭’ ‬with the latin‭ ‘‬draco‭’ ‬which means‭ ‘‬dragon‭’‬.‭ ‬The species name‭ ‘‬venator‭’ ‬means‭ ‘‬hunter‭’ ‬and combines with the genus name to make Guidraco venator which means‭ ‘‬ghost dragon hunter‭’‬.

       Guidraco is merely one of many pterosaur genera that are known from the Jiufotang Formation of China.‭ ‬Below is a list of some of the pterosaurs that have been recovered from this Formation.

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