sexta-feira, 28 de novembro de 2008

Pterosaurs for Spec (part 1)

Suggestions for Spec (and, in case refused, to my personal projects). Part 2 coming (I'm simply to lazy to right everything in the same day).
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Like HE, Spec has birds and bats. However, if one notes carefully, he/she will find that, despiste the appearent similarities, the winged vertebrates of both timelines are different. Birds, for instance, aren't all within the Neornithe clade, the only surviving dinosaur clade in HE; some are Enantiornithes, or "opposite-birds", others are related to Neornithes (such birds belong to the two toothed sea birds orders and to a single order of pigeon like birds), other are part of the bizarre Xenornithe clade, and others may or may not be birds at all. And bats aren't even true bats; there are two winged mammalian clades, one that consists on primitive, egg laying mammals, and another on winged primates with what seems to be Mammalia's answer to maniraptor feathers.

However, there''s a clade of flying tetrapods that clearly makes Spec unique: pterosaurs. These flying archosaurs, related to dinosaurs, have ruled the skies since the dusk of the Triassic, and even after the appearence of birds they remained kings of the air, indeed, these produced the biggest flying beasts ever, some with wingspans of 12 meters or more. On HE, these magnificient beasts disappeared from the skies (though their fossilized remains clearly affected human imagination; after all, who doesn't picture a toothed, long tailed Pteranodon, no matter how inaccurate it is?), but on Spec, they still remain, and though their days of kings of the sky are long gone they still enjoy a cosmopolitian distribution, and some still reach great sizes, while others are among Australia's dominant predators.

Pterosaurs have unique features that separate them from other sauropsids. Their wings are leathery, supported by a very long finger fourth finger (the other three are clawed, and used to climb, grom and support their weight) and strong fibers; they also have a smaller patagia, that extends from the wrist to the shoulder, and which is also supported by the pteroyd (a long bone that extends from the wrist), unique to this clade; this, alongside the webbed, clawed fingers of the hand, has the function of an avian bastard wing, or alula. Pterosaurs have plantigrade hind feet, but the front limbs have elongated metacarpals, an adaptation to the support of the wing membrane. Pterosaurs, like most "reptiles", are highly precocial; the young ones, or "flaplings", can already fly from the moment they are born. Therefore, while parents might protect the eggs, the young fend for themselves; this means adults and babies occupy different niches, thus decreasing their specie diversity.

Pterosaur fossil record in the Late Cretaceous is poor; only two clades, Azhdarchidae and Nyctosauridae, are well known, though there are several fragmentary remains. It was once believed that they disappeared as birds took over the skies and outcompeted them, but, while a decline in diversity can't be totally ruled out, it doesn't seem to had been caused by avians. By the Paleocene/Eocene thermal maximum, it is pretty clear that the pelagic nyctosaurids were wiped out, incapable of long term survival when the marine ecosystems suffered rapid changes. However, soonly afterwards, pterosaur taxa which left no remains since the Early Cretaceous reappear; the small, insectivorous Anurognathidae are common in the sediments of Messel in Germany, which date from this era; other pterosaurs also reappear as well. The already mentioned azhdarchids also saw a small wave of diversification; traditionally strok-like, some gave rise to hornbill-like forms, like †Gigantala. The end of the Paleogene saw the decline of some old pterosaur taxa, while the azhdarchian pterosaurs produced the scavenger rocs, and the flightless carnocursorids. Current pterosaur diversity is mainly based on anurognathids and azhdarchids, though some oddball species still remain.

Anurognathidae

The most basal modern pterosaur taxa, they seem to be a sauropsid's answer to a mammalian bat. Small and with a short, broad snout (similar to that of a frog), they occupy a niche akin to that of HE's nightjars and frogmouths, sharing the night skies with flying mammals and leaving the daylight to birds. This group is quite ancient, having its origin steaming from the Early Jurassic (and possibly Early Triassic), but their skeletons, so fragile, have only left fossils in the middle of the Mesozoic, from the Late Jurassic to the Early Cretaceous. They later reappear in the Cenezoic, when places with the apropriate conditions for their fossils to be preserved occured again.

Most modern anurognathids are insectivores like their ancestor, but a few are vertebrate predators.

Cliff-Ghast (Europteryx philippullmani)

A typical anurognathid, this black and brown insect eater occurs in Europe, wintering in Africa and India. Its name comes from its prefered rosting places: cliffs. During the day thousands of these ghasts gather in mountainous or coastoal cliffs to rest, trusting on their coloration to protect them from predators. Then, at dusk, they suddenly erupt from their roosting positions and fly acorss the mainland in search of food; some cliff-ghasts tagged on the Alps have been found on Britain in the same day. During the spring, males form leks on the cliffs, mating with any female that passes nearby and fighting off competitors. Afterwards, the fertilised females bury their eggs on the ground; the flaplings hatch 20 days or so after they had been layed.

Blue Paradise-Dactyl (Ranorhynchus paradisea)

Denizens from New Guinea, paradise-dactyls are perhaps the most colorfull of all anurognathids. The males of this specie has beutifull bright blue wings, though other species have quills males in addition to bright colors (no anurognathids have crests). They are also active in the daylight, leaving the night time to their relatives, the ghasts. They also have nectar added to their diet, making them the only pterosaurs specialized in drinking nectar while adults (though flaplings of other pterosaurs do take nectar).

Tengu (Daemonognathus niponica)

Although most anurognathids are insectivores, the tengus have strayed from the family's habits and became powerfull vertebrate killers. Barely avoiding competion from the avian scowls, they also hunt them, specially when they are chicks. In turn, scowls eat their flaplings. This aprticular specie is endemic to Japan and the first described specie; other tengus occur in mainland Asia and Ocenia. Tengus, being actual carnivores, are solitary, as opposed to their flock forming relatives; the territory of a male often overlaps those of several females. Other males are kept at bay by their powerfull agressivity; battles often end in death.

Pterodactyloidea

Aside from anurognathids, all living pterosaurs belong to this clade. The most diverse clade is azhdarchoidea, but there's a few oddball species.

Kongamato (Amphipterus africanus)

An unique african pterosaur, this creature resembles †Cearadactylus from the Early Cretaceous, though it might not be related. With a wingspan of 3 metres, this creature occurs in the wetlands and waterways in Africa and Madagascar. Dwarved by the rocs, this creature is, unlike them, an active predator, hunting fish and small animals from the air; it has been reported to attack olitiaus (azhdarchids that resemble hornbills). Solitary and territorial, it oftens attacks specsplorers that dare to venture into their habitat. As such, little is known from their breeding grounds.

Ropen (Luciopterosaurus aumalae)

Similar to the kongamato, this creature is considerably less agressive, though its prefered habitats, the dense forests and wetlands of New Guinea and nearby islands, make it hard to study them. This creature is the only pterosaur to have bioluminescense; its patagia glow brightly in the night time. It is presumably caused by a specie of fungi, probably related to the fungi that infects baskervilles.

(azhdarchoids are left for the next essay)

terça-feira, 25 de novembro de 2008

Paleognaths: an essay for Spec

I'm gonna post all essays for Spec here. Hopefully I won't have (very) negative answers.

Note: includes ideas of my own.
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When the first explorers went to Spec they saw a large number of birds very similar to HE's. In fact, some were so familiar that they were directly classified without any particular studies. The several dove like birds, for instance, were all classified as Collumbiformes, while any passerine like bird was directed to the Passeriformes order. However, later genetic and morphological studies prooved that Spec's biologists were wrong, and most if not all Spec's "familiar" birds aren't familiar at all (except for ancient birds like penguins and fowl, which were already present in the late Cretaceous). For instance, the "doves" were actually aberrant euornithes outside of the neornithe clade, while "passerines" were typical enantiornithes. As of yet, the familiar birds that are within neornithes haven't revealed their mysteries; no conclusive data has come from p-Apodiformes, p-Coraciiformes and p-Piciformes yet (though Spec's Piciformes do seem to have diverged from Coraciiformes, as in our world's Piciformes, and both clades seem to be related to Spadaviformes, loosely similar to the clade that includes hornbills and hoopoes in HE; given the fact that there's no known caprimulgiformes from Spec, the classification of its Apodiformes is more controversial, as in HE they are derived from nightjars and kin), but we do know that Spec's shorebirds, rails and cranes aren't neither Charadriiformes nor Gruiiformes. They are Paleognaths, relatives of HE's ratites.

Neornithe history in the late Cretaceous is not very well known; apart from the waterfowl Vegavis, all neornithe fossils from then are highly fragmentary (like those of nearly all birds); it is often assumed though that, aside from the already distinct Galloanserae (waterfowl and fowl), the forerunners of the modern bird groups were nearly all shorebird like, as the forerunners of placental and marsupial mammals were nearly all rodent or shrew like, and only in the Paleocene did they became diverse. Eventually, in both timelines a single bird order took over the all shorebird niches; in HE, it was the Charadriiformes (although Ciconiiformes did produced the probing ibises and spoonbills), but in Spec it were the paleognathian Lithiorniformes. While ratites never evolved with non-avian maniraptors around (if we ignore the large island paleognaths; see below), the descendents of early probing paleognath †Lithiornis (present in both timelines) became very diverse and now occur in all landmasses; they also expanded into other niches besides those of shorebirds, including rails, cranes, bustards, ibises, kiwis and some large island forms.

Lithiornidae

While †Lithiornis itself is dead, its descendents occur all over the world. They took the niches of sandpipers, ibises and other probing birds everywhere (aside from those of small probing birds, like plovers; see below). Because of their wroldwide success at more 600 species, and because most of their diversity is annoyingly similar to that of their HE analogues, we are only going to show a few species.

Rectal probe (Scatornis benseni)

Spec's most bizarre (and appearently most disgusting) lithiornid occurs in South America, specifically in the Amazon Basin, exactly were the pseudosauropod Aquatitan (Aquatitan boothi) lives; the small, head-feather-less rectal probe has an interesting symbiotic relationship with the ornithician: it feeds on the parasites that infect its cloaca, and in turn infects them.

Tasmanian mudpiper (Enantioprosobonia byroni)

A typical member of the lithiornid family, this bird occurs in southern Australasia, being very common in Tasmania and New Zealand; sometimes, it occurs as a vagrant as north as New Caledonia. During the summer it occurs in wetlands, preffering to winter in the coastline. These birds have an unique breeding behaviour, practised by all mudpipers; males often form couples, mating with females in order for them to lay eggs in their nest. This behaviour is seen in HE's black swans, but mudpipers are unique because they solely form male/male couples, unlike black swans, which can also use the traditional monogamous couples, male/female. This strategy beneficts both the chicks and the females, as the first have better chances of surviving with two males prottecting them, while the later can spread their genes much better without being stuck to a single partner.

Iblis (Daemonibis arabica)

Named after the devil of Islam, this ibis like bird occurs in coastoal ecosystems from the Red Sea to India. Coloured like HE's flamingoes, it obtains the pink pigment from the invertebrates that they eat. True to their name, they are truly nasty; in the mating season, males engage in terrtitorial battles that nearly always lead to mutilations and sometimes death. They have also been reported attacking other animals; some lemmecks that venture to the coast end up without an eye or worst. Females are also very protective of their young. Despiste being precocial birds, like all paleognaths, baby iblises have a strong rivalty with their siblings like nidiculous birds, and if not eaten by predators they die killed by their stronger brothers and/or sisters.

P-Kiwi (Pseudoapteryx spp.)

While Spec's New Zealand is different from HE's, it also has annoying similarities. P-kiwis are very similar to HE's: both are nocturnal birds that probe the ground with their long bills in search of worms and other invertebrates. Unlike HE's kiwis, however, these ones have bigger clucthes; after all, they live in a place were predatory birds like fells, the gobbler and toothed enantiornithes are not uncommon.

Pseudogruidae

In addition to the wader-like lithiornids there are also the rail, bustard, buttonquail, crane and tinamou like pseudogruids. They seem to be an offshot of the linage that gave rise to ratites in HE. Again, we will only present a few species, though there are at least 900 modern forms

Galapagou (Galapagotinamus spp.)

Similar to HE's tinamous from South America, the galapagous are however restricted to the Galapagos, though fossil species do occur in South America. It is believed that competion from galliformes caused their extinction in the mainland.

Macaronesian arsequail (Specturnix macaronesia)

A small landbird, this creature belongs to a group that mimics HE's buttonquails. This particular specie occurs in the eastern macaronesian islands, the Madeira and Canary archipelagos. Not very different from mainland kinds, this is a little generalist that feeds mostly on invertebrates, thus avoiding competion with the more granivorous galliformes. This particular specie is a true pest to the native flightless gondwanaviforme known as Frango (Scythornis insularis); this birds diet is composed up to 20% of the enantironithe's eggs, and and in dry seasons it even makes hounds on its chicks in order to drink the blood. But adult frangos are far from careless, and its not unusual for an arsequail to die at one's claws.

Polokai (Tetraorallus aeteroa)

Spec's takahe, this bird resembles a turkey sized moorhen. Heavy and fligthless, one could think such a beast would not exist with menacing fells nearby, but it isn't completly harmless. These birds are very agressive, and like HE's cassowaries they have powerfull claws in their feet; a single fells most likely dies while attacking one rather than killing one; though, in desesperate times, a flock of fells might gather to attack one, and in that case the result is a feast for the toothed birds.

Gobbler (Diablornis giganteus)

The polokai's closest relative, the gobbler is Spec's closest analogue to a ratite, though in terms of behaviour its more like a vulgure than a moa, eating anything that fits on its broad bill. As tall as a man, it surprisingly represents little threat to anything larger than a p-kiwi. It is specially well known for raiding gigaduck nests, so the giant waterfowl protect viciously their chicks and eggs. The gobbler is also a notable scavenger, often driving fells and predatory enantiornithes off their kills.

Fenghuan (Pseudogrus paradisea)

Out of all of Spec's false-cranes, none is more magnificient than the fenghuan. Taller than a man, this white, grey and black bird is only dwarved by the azhdarchid pterosaurs and the pseudodontorns in being the largest flying animal. It occurs in the wetlands of all of eastern Asia, leaving the Europe and western Asia to its smaller cousins. Too aquatic and too herbivorous to compete with the azhdarchids, this creature is still regularly observed in their company; perhaps the birds seek protection in the middle of a pterosaur's flock, or perhaps the false-crane feeds on the insects that the flying reptiles ignore. Fenghuans form monogamous pairs that can be life-long, thought they can "divorce" in case the couple can't produce chicks for a considerable period of time. Many older birds have at least one of their eyes white; this result of the infection of a fungus related to those that live in a baskerville's body. This phenomenon is called "white blindness", even though the birds don't seem to become blind.

sábado, 22 de novembro de 2008

Spec

The Speculative Dinosaur Project, or Spec, is, for those that don't know about it, a project about our world if dinosaurs (or any other group from the late Cretaceous that disappeared) didn't become extinct. It started as a somewhat inaccurate project that has suffered massive editings lately; the site itself (which is just an experimentaion one; the official bowdoin site is down for good) isn't very different from its original version, but the yahoo group is quite active at the moment; in fact, if I was to write Spec's pages according to the current situation, you would find that Spec has changed completly.

For instance, many solid groups of old Spec are gone, such as the salmonites, the hesperonychids, the behemoths and probably even the abelisaurs (given the fact that RL abelisaurs weren't cursorial, all fast running species of Spec will be gone or remade). The arbros have been divided into two groups (and probably will be reworked), mattiraptors are in a totally uncertain situation (they will either end up as birds or as unenlagiines), paraselenodonts, troodontids, sauropods and others have fine new additions, arjuns passed from hesperornithes to icthyornithes and malagasy mammals from marsupials to placentals, and groups previously extinct like pterosaurs are now a strong presence on Spec's world (so much that the avian rocs are gone). Em fim, this maelstrom of ideas is currently shaping Spec to the point that the final product will be completly different from the old one. I personaly like Spec, and I hope the book (yes, there will be a book) is ready, as well as the site. 'till then, I'll try to help the staff (now only 4/5 members of the original team remain, plus a new addition from Puerto Rico) to make it as accurate as possible.

The bigger issues now are within maniraptora and the cave and mangrove ecosystems. After that, its pterosauria and choristodera, and it will perhaps be ready.

The beggining

After what it seemed an eternity I decidedo open my blog. Its not the first time I've made an attempt at making one, but I will use this one (that is, unless someone steals it...)

Anyway, this blog will be used for two main things:

-to host my reviews on books/movies/whatever

-and to host my essays

To those that don't know me, I'm a biology afficionado (specially regarding evolution), but I'm also interested in the furry fandom. I'm by no means american nor british - I'm from Portugal, and while english will be the main language used here I will not refrain from using portuguese (and mandarin).

Cheers for everyone!