Membrane filter paper : Aquarium filter not working : Vari nd filter
Membrane Filter Paper
Microfiltration is a filtration process which removes contaminants from a fluid (liquid & gas) by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometres (µm).
a thin microporous material of specific pore size used to filter bacteria, algae, and other very small particles from water
a solid continuous film of material that has microscopic pores of controlled size.
Material manufactured in thin sheets from the pulp of wood or other fibrous substances, used for writing, drawing, or printing on, or as wrapping material
cover with paper; "paper the box"
A newspaper
Wallpaper
a material made of cellulose pulp derived mainly from wood or rags or certain grasses
composition: an essay (especially one written as an assignment); "he got an A on his composition"
pteranodon longiceps
This model represents the smaller from the only two recently considered valid species of Pteranodon, but as the two differed only in the shape of the crest. (except for the size, which doesn't matter now) I can easily make it to resemble P. sternbergi. =P
P. sternbergi (the larger and earlier species) measured up to 7 m from wingtip to wingtip, which makes it one of the largest flying animals ever. only the lower jaw itself was 1.25 m long.
P. longiceps was smaller, growing up to 5 meters from wingtip to wingtip.
Because the range on the timeline of both species didn’t overlap, or if so, only very slightly, it is highly possible P. longiceps evolved from P. sternbergi.
Pteranodon was the first pterosaur found somewhere else than in Europe and the first pterosaur found in North America.
A similar species called Nyctosaurus sported very similar features - long narrow wings, crest on the head, but thinner, bifurcated, with a long branch sticking backwards, which was earlier thought to be short. It was first thought to have been webbed with a thin skin membrane, but it was disproved later, because the bone was totally smooth with no rough attachment surfaces which are present in pterosaurs with membranous crests, such as Tapejara.
It was a very rare species. It also was much smaller than Pteranodon, reaching adult wingspan of only 2 meters and weight of 2 kg.
It differed from Pteranodon (and other pterosaurs for that matter) in one thing, It had no hand on the wing, so it probably was almost exclusively aerial, flying and/or gliding all the time, probably landing only for the means of sleep, mating and laying eggs, because the lack of paws disabled it to grab on rough surfaces, so it probably was much goofier on land than other pterosaurs. (There were some taxa well-adapted for terrestrial locomotion actually, such as Quetzalcoatlus).
My model represents a mature male Pteranodon, females and juveniles had small rounded crests. The sexual dimorphism of Pteranodon wasn't only focused on the size of the crests, but also on the size of the entire animal. The females reached only 2/3 of male dimensions, only up to 4 - 5 meters from wingtip to wingtip.
The model is folded from a 50 cm sheet of tissue foil and the finished model has 50 cm wingspan, so it's a 1:14 model with efficient ratio 1:1. =P
Pteranodon used all four feet for terrestrial locomotion - it was a tetrapod just like any other pterosaur.
Though there were pterosaurs in the triassic and jurassic, the age of ramphorhynchoids (those with tail), it lived in the cretaceous period, where pterodactyloids (those without tail) were common.
Thanks to the high number of Pteranodon fossils (1,200 speciemens!!!), it is one of the best-studied extinct species.
It is now known all pterosaurs were active, rapidly growing and warm blooded animals with bodies covered in a layer of fur- or simple feather-like structures, nicknamed "ptero-fuzz" for short. =P
It can maybe look weird, but there were animals which fed on Pteranodon! Such as mosasaurs and huge fish that lived at that time. Pteranodon had similar wing ratio (width to wingspan) to recent albatross (Pteranodon - 1:8; albatross 1:7) so the scientists believe Pteranodon was also an active ocean soarer, so a large fish or mosasaur could just jump and catch it in flight. I’m a bit suspecious about it being common, I doubt Pteranodon would voluntarily, or when it wasn’t absolutely necessary, glide low enough for longer periods of time to be easily cought by the sea predators, but there is an evidence of Pteranodon bones in stomachs of mosasaurs, but I have always wondered how they could tell the mosasaur just didn't eat a dead one...
It was long imagined to fly in low altitude, skimming to catch fish, but the thing is, being much bigger than recent skimming seabirds, such as terns, it was hypothesized the drag would be much larger, putting the creature's neck under an immense strain when holding its head in a close-to-normal position, with jaws open and dragging the chin in the water.
There was only one group of pterosaurs which could use skimming for feeding known so far. They were the mighty ornithocheirids, pterodactyloid pterosaurs, in some cases comparable to Pteranodon in size, with Ornithocheirus (a 2.5 and a 6 m wingspan specimens are known), Tropeognathus and Criorhynchus, which are now seen as Ornithocheirus symonyms, also reaching 5 - 6 m from wingtip to wingtip. Another note-worthy one is Anhanguera, not terribly smaller than the previous three (or actually one, for that matter), reaching 4 m in wingspan.
As I mentioned the skimming above, Anhanguera and its relatives would rather bend their neck downwards so that the jaws were held under the body and sloped at a 45 degree angle towards the water
Paper
Many days of hard work, some drops of ink, a lot of MC, Tissuepaper and "Silk"paper ^-^
Output: 52 Sheets in different shapes (squares and rectangles), sizes and colors.
Gerwin Sturm told me that doubletissue is perfect to fold tessellations and I have to admit, it's really nice to fold ^-^ Thanks for the hint...