Saturday, October 10, 2015

October unleashed. Nyctosaurus

Although many pterosaurs sported elaborate head crests,‭ ‬Nyctosaurus took things to a new extreme.‭ ‬Rising up to over half a meter high,‭ ‬a proportionately massive‭ '‬L‭' ‬shaped crest is known to have been present on Nyctosaurus.‭ ‬This crest was once thought to have been the support for a skin sail,‭ ‬but today it is generally accepted that the crest was more or less as it was preserved,‭ ‬with it sometimes being referred to as a pterosaur‭ '‬deer antler‭' ‬from its appearance.‭ ‬Although it may appear cumbersome,‭ ‬the crest was actually very light,‭ ‬and studies have shown it would have had very little impact upon the flying ability of Nyctosaurus.‭ ‬It is however somewhat harder to say if it actually imparted any positive benefits.
       Study of sub‭ ‬adult specimens has raised the notion that Nyctosaurus reached full size within its first year,‭ ‬and that the crest started growing when the individual in question reached adulthood.‭ ‬The crest may have been growing throughout the entire adult life of Nyctosaurus,‭ ‬with the largest crests belonging to the oldest,‭ ‬and henceforth most successful individuals.‭ ‬This would serve to persuade potential mates that the larger crest was superior to the smaller.
       Another special feature of Nyctosaurus is the complete absence of claws from the first,‭ ‬second and third digits of the hand.‭ ‬This means that Nyctosaurus would have had a hard time clinging onto things while on the ground and has brought the suggestion that Nyctosaurus may have spent most of its time flying in the air.‭ ‬A potential benefit of the lack of claws however is that the wings would have been even more streamlined.‭ ‬Because the fossils of Nyctosaurus are known from the Niobrara Formation,‭ ‬it's a safe assumption that it would have flown over the Western Interior Seaway while looking for fish.
       With the exception of the head crest being completely different,‭ ‬Nyctosaurus often draws comparisons with the well-known pterosaur,‭ ‬Pteranodon.‭ ‬Not only do they have similar body morphology,‭ ‬both Nyctosaurus and Pteranodon have been found in the same fossil formation,‭ ‬and both would have shared the skies of the late Cretaceous at the same time as one another.‭ ‬However Nyctosaurus has a much shorter presence in the fossil record of approximately only half a million years,‭ ‬whereas Pteranodon spanned over seven million years.
       Because of its similar body morphology to Pteranodon,‭ ‬Nyctosaurus may have flown in a similar manner,‭ ‬including using a process known as dynamic soaring.‭ ‬Dynamic soaring is where a flying creature such as an Albatross flies into the trough formed by two waves and into the lee of a passing wave.‭ ‬The lee is the change that results in stronger air pressure that occurs as the wave moves along,‭ ‬and this pressure results in air moving faster over the wings and increasing their lift.‭ ‬The animal in question can then turn around sharply,‭ ‬a process called‭ '‬wheeling‭'‬,‭ ‬and then head back towards the trough with a back wind that further increases speed.
       The number of species attributed to Nyctosaurus has changed since its discovery,‭ ‬and even some of the species listed above may yet prove to be identical to the type species.‭ ‬Only time with further study and hopefully new fossils will be able to establish the exact species with certainty.

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