Comments

1. #1 Andreas Johansson

   October 9, 2008

   On the subject of bad dinosaur names, Stephanoaetus coronatus appears to mean “crowned crowned eagle”.

2. #2 Darren Naish

   October 9, 2008

   Yes, that’s because it was originally Falco coronatus Linnaeus, 1766. By the late 1800s it was being included in Spizaetus and not until 1922 did W. L. Sclater decide that it needed its own genus.

3. #3 Jerzy

   October 9, 2008

   Bearded vultures attacking man is, I think, referenced in HBW.

   BTW, Mongols trained golden eagles to attack humans. I doubt this was very effective weapon and eagle lived long, but still…

4. #4 Bill

   October 9, 2008

   A few years back I watched a video on line of an eagle (in Mongolia I think) take down a small deer. It’s impressive that hazards predators assume when at work, eagle no less than lion. The eagle knocked down the deer. With talons dug in, predator and prey summersaulted together at least once, the eagle had to struggle to end up on top. It gave me a whole new take birds. It looked quite like a lion rolling a buffalo.

5. #5 Darren Naish

   October 9, 2008

   Bill, you might be referring to the video I posted here (though I’m not saying of course that Tet Zoo is the only place on the web where you might see it: I learnt about it from Querencia).

6. #6 anon comment

   October 9, 2008

   On the subject of bad dinosaur names, Scrotum humanum not only appears to mean “human scrotum”, it *does* mean “human scrotum”.

   http://en.wikipedia.org/wiki/Megalosaurus

7. #7 Darren Naish

   October 9, 2008

   But note that ‘Scrotum humanum’ was *never* used as a name, only as a label on a plate: this was by Richard Brookes in 1764. Some authors (notably Halstead & Sarjeant 1993) have written of ‘Scrotum humanum’ as if Brookes intended it to be used as a binomial, but there’s no indication of this – all he did was illustrate the specimen and put the label ‘Scrotum humanum’ next to it. This was realised by P. K. Tubbs of the ICZN who responded to Halstead & Sarjeant’s ICZN petition to ‘suppress the generic name Scrotum‘ and basically said that they were mistaken for the reasons I’ve given above. I don’t know about Sarjeant, but I never thought that Halstead took this claim seriously anyway.

   Ref – -

   Halstead, L. B. & Sarjeant, W. A. S. 1993. Scrotum humanum Brookes – the earliest name for a dinosaur? Modern Geology 18, 221-224.

8. #8 Jerzy

   October 9, 2008

   Coming to English names, Lammergeier (lamb vulture) was renamed Bearded Vulture/Bartgeier for PR reasons.

   And insignificant but endangered rodent from Philippines named Panay Cloud Rat (I think it lives in cloud forest on island Panay) was renamed into somewhat poetic Panay Cloudrunner.
   )

9. #9 Steve Bodio

   October 9, 2008

   Good to see this back again wit some nice new pix.

   “Mongols”– actually Kazakhs in Mongolia and elsewhere— still hunt foxes, wolves, and various hoofed things with eagles– I have been there, and written a book about it (Eagle Dreams.)

   In the Czech Republic there is a falconry festival every year where golden eagles are flown at roe deer in large fields where they graze. They take them as easily as a goshawk does a hare. There are various versions on YouTube.

   Meinertzhagen claimed that a lammergeier stooped sat him while he was traversing a mountain ridge. Of course there are those who will tell you that he was not the most truthful man alive…

10. #10 Mike Dickison

    October 9, 2008

    Yes, Haast’s Eagle routinely killed moa 100 kg or larger (up to 200 kg Dinornis). So it would have been preadapted to hunt humans when they arrived here in New Zealand. No wonder they went extinct so fast.

    Haast’s Eagle had some vulturine skull adaptations (elongated beak, nostrils partially occluded with bony scrolls, etc) presumably because it had to plunge its head right into the bowels of its prey. Do any of the other predatory eagles mentioned above have some of the same adaptations, or are large animals not a common enough prey item for such things to evolve?

11. #11 Darren Naish

    October 9, 2008

    Mike: so far as we know, Haast’s eagle was unique as goes its vulturine and terrestrial adaptations. As you know, it’s probably not coincidental that it evolved in a land devoid of large terrestrial predators. In other words, ‘We know from well documented taphonomic evidence that Haast’s eagle could and did kill even the very biggest of the contemporary moa, and unlike big eagles in continental environments it could probably get away with gorging itself at a carcass without having to worry about flying off in a hurry’. That’s from here.

    Haast’s eagle was also covered on Tet Zoo ver 1 here.

    Based on Haast’s eagle, we might speculate that established terrestrial predators (namely carnivorous mammals, both placentals and marsupials) have prevented eagles from becoming strongly terrestrial in continental environments.

12. #12 anon comment

    October 9, 2008

    “note that ‘Scrotum humanum’ was *never* used as a name”

    Sure. But even so – did his buddies dare him to do this after one too many bottles of port, or what?

    (Second favorite [real] goofy dino name: Irritator.)

    http://en.wikipedia.org/wiki/Irritator

    (Whoa, special trivia bonus! — it’s Irritator challengeri, after *the* Professor Challenger. Style points to Martill, Cruikshank, Frey, Small and Clarke.)

13. #13 Banks Miller

    October 9, 2008

    I’m surprised the Haast’s eagles didn’t *win*. How many were there? Surely there were more of them than humans at first…

    I hoped that’s why it was challengeri. I liked that book.

14. #14 Allen Hazen

    October 9, 2008

    Darren– I periodically reread your old posts ANYWAY, but this was well worthwhile: new pictures, new comments, and new old Christmas card! Nice post.
    —
    Hmm. If some people have thought that “Scrotum humanum” was close enough to being a Linnean binomial to be worth petitioning the ICZN about, are there people who think that a full systematic story about gian salamanders has to mention a supposed “Homo diluvii” (subspecies: testis)?

15. #15 Christopher Taylor

    October 9, 2008

    Homo diluvii testis is not a subspecies name, diluvii testis is a descriptive phrase published as a unit. Taxon names were generally polynomial before the introduction of binomial nomenclature, and as Homo diluvii testis dates to 1732 it pre-dates the official beginning of valid zoological nomenclature in 1758.

    (The only pre-1758 publication accepted by the ICZN is Clerck’s Aranei Svecici of 1757, which would officially make Araneus the first genus ever published.)

16. #16 R.A.W.

    October 10, 2008

    I’m surprised the Haast’s eagles didn’t *win*. How many were there? Surely there were more of them than humans at first…

    Compare dates of the definitive colonization of New Zealand with the rest of the Polynesian Pacific.

    Who’s to say that they didn’t win at first?

17. #17 Dartian

    October 10, 2008

    First of all, thanks for re-posting these old articles, Darren! Will you re-post them all, or just a select few?

    In fact the ability of large eagles, specifically Golden eagles, to kill relatively enormous prey is not doubted and well established. Between 1987 and 1989 representatives of Animal Damage Control (ADC) were called in to check out mysterious domestic cattle deaths that were occurring in Socorro County, New Mexico. 6 calves were killed and 13 injured, with the biggest calf attacked weighing 115 kg. The attacks were caused, unquestionably, by a pair of local Golden eagles, as verified by observed attacks and by the talon marks on calf skulls.

    I am slightly hesitant to point this out, as it usually turns out that you already know anything tetrapod-related. But are you aware that there is, besides eagles, another documented cattle-killing bird species? That species is the American black vulture (Coragyps atratus).

    Black vultures mostly eat carrion but they have been recorded to harass and kill fairly large animals in feeding frenzy-styled mob attacks. McIlhenny (1939) described, in quite chilling detail, such attacks on skunks and opossums; the unfortunate victims were literally torn apart by the vultures. (Incidentally, the skunks’ chemical defences seem to be wholly inefficient to deter such attacks.)

    In some parts of the US, black vultures are also a serious problem for livestock breeders, as they kill newborn piglets, lambs and even calves (Lowney, 1999; Avery & Cummings, 2004). These attacks typically occur when the vultures spot an animal out on pasture that’s about to give birth. Usually the vultures settle for the afterbirth, but if the mother is too exhausted or inexperienced to defend her offspring, the vultures will attack it (by first pecking out its eyes). Sometimes the vultures even attempt to attack the adult cow in the same way.

    In fact, perhaps Coragyps is the closest living analogy we have to Velociraptor…

    References:

    Avery, M.L. & Cummings, J.L. 2004. Livestock depredations by black vultures and golden eagles. Sheep & Goat Research Journal 19, 58-63.

    McIlhenny, E.A. 1939. Feeding habits of the black vulture. The Auk 56, 472-474.

    Lowney, M.S. 1999. Damage by black and turkey vultures in Virginia, 1990-1996. Wildlife Society Bulletin 27, 715-719.

18. #18 kai

    October 10, 2008

    So basically this boils down to a question of the load-carrying capacity of African and European eagles. Are there any predatory swallows involved?

19. #19 wazza

    October 10, 2008

    As for Haast’s Eagle driving humans out of NZ, their range never covered both islands, so far as I know, and so it was probably possible for the Maori to establish a foothold before going eagle hunting.

    Even so, there are some myths of young Maori being kidnapped and terrorized by bird-women…

20. #20 Sordes

    October 10, 2008

    Last year several crows (or ravens, this was not that sure) attacked and killed seven lambs in Austria. Just imagine what raptors could do when they would hunt in bigger packs.

21. #21 Jerzy

    October 10, 2008

    I read that a group of Griffon Vultures killed a cow in Spain in mass attack, when cow laid down. It happened when BSE scare led people to remove cattle carcasses and vultures were starving. But it was just newspaper news.

22. #22 David Marjanovi?

    October 10, 2008

    But even so – did his buddies dare him to do this after one too many bottles of port, or what?

    No. He honestly believed the thing was a petrified human scrotum. Keep in mind that paleontology didn’t exist yet; Linnaeus classified all fossils in the mineral kingdom, not the animal and plant kingdoms.

23. #23 Jerzy

    October 10, 2008

    Perhaps the reason why no bird of prey hunts big animals in groups is competition from larger predators. Group of 10 eagles might kill a deer, but would not defend it from a lion.

24. #24 Jerzy

    October 10, 2008

    Off topic, but fitting the blog: Nile crocodile in a gallop:

    http://bernstein.smugmug.com/gallery/6185446_Z9Aru#390185942_WpDkJ
    (bernstein > Round the World Trip > Malawi > Liwonde , pic 38 of 59)

25. #25 Tengu

    October 10, 2008

    Linnaeus classified all fossils in the mineral kingdom, not the animal and plant kingdoms.

    But he was right; Fossils are minerals, and not animals or plants, thats what fossilisation means, after all.

    Fastinating guy; but what was it with the Shaman costume??

26. #26 DDeden

    October 10, 2008

    OT: Solar powered flight? (hope no errors)

    cold blooded: tiktaalik, amphibians
    cool blooded: archosaurs, reptiles
    warm blooded: dinosaurs, pterosaurs
    hot blooded: birds, mammals

    cold blooded = water/mud adapted (+ naked mole rat)
    hot blooded = land/air adapted

    Since bats fly at night, they must be hot blooded, but may have originated as diurnal canopy gliders (w/o owls)?

    Did the wide spanned pterodactyles use their wings to absorb solar energy to warm their blood for powered gliding/flight? Could that have been the origin of wings among those perching on sunny tree/cliff tops? The addition
    of downy feathers in birds indicate no more need for sunlight, so increased homeothermy? Then flight feathers developed? Canopy animals unlike ground and water animals are already light boned and sun warmed, if they consume sugary saps, flower nectar, sweet fruit, flying insects then homeothermy is a good option, adding skin flaps on the forelimbs would allow speedy tree to tree transit.

27. #27 Jerzy

    October 10, 2008

    @DDeden
    If you mean zoological speculation, ratio of surface to volume and efficency of photosynthesis conspired together, and say that active sunlight-powered animals bigger than few millimeters are impossible.

28. #28 shiva

    October 10, 2008

    I don’t think DDEden is talking about photosynthesis; i think ze’s talking about solar-thermal energy, as used by living squamates in areas with cold nights. Ever seen an adder or a sand lizard “sunning itself”?

    Converting solar energy into any other kind of energy through any kind of chemical process is vastly inefficient, which is why photovoltaic electricity isn’t really viable outside the tropics. But using it directly to heat water (or blood) is very easy and very efficient.

    I think the speculation is that, assuming pterosaurs were not fully homeothermic, they would have needed to increase their body temperature to be active enough for powered flight, and thus the very large skin area of their wing membranes could have played a role in heating them more efficiently (which would make the best reconstruction be with the membranes being dark coloured).

    There are probably reasons why this is unlikely, but i don’t think it’s as out there as suggesting that pterosaurs could photosynthesize…

29. #29 David Marjanovi?

    October 10, 2008

    DDeden, I don’t know where to begin. You should first learn something about these several topics before talking about them.

    For starters, there is no difference between “warm-blooded” and “hot-blooded”.

    Canopy animals unlike ground and water animals are already light boned

    Wrong.

    and sun warmed,

    Also wrong — it’s always cooler in forests than outside (except sometimes when it’s below freezing and there’s wind chilling).

    if they consume sugary saps, flower nectar, sweet fruit, flying insects then homeothermy is a good option,

    I don’t see why. Also, flower nectar and fruits did not exist before near the end of the Early Cretaceous.

    adding skin flaps on the forelimbs would allow speedy tree to tree transit.

    Leading to gliding — but whether flapping can evolve from gliding is controversial.

    Converting solar energy into any other kind of energy through any kind of chemical process

    is not done by animals except those with photosynthetic endosymbionts (like shallow-water corals). Heat from the sun can raise the body temperature so that the metabolism can work at its maximum speed, but it can’t increase that maximum speed, which is usually much higher in warm-blooded than in cold-blooded animals. If you give a lizard heat but no food for long enough, it won’t run around but starve.

    assuming pterosaurs were not fully homeothermic

    There is no reason for such an assumption.

30. #30 shiva

    October 10, 2008

    ” Converting solar energy into any other kind of energy through any kind of chemical process

    is not done by animals”

    I am aware of this, just didn’t think it necessary to point out. Possibly i was guilty of trying too hard to find something approaching plausibility…

    Is there evidence that pterosaurs *were* fully homeothermic?

    (I’m getting increasingly fascinated by pterosaurs, and just how “out there” they were. Animals like Tapejara, Nyctosaurus and Hatzegopteryx just seem like they couldn’t possibly have been imagined even by the wildest-imaginationed fiction writer. I can’t even begin to imagine what they would have looked like in flight, it’s kind of mind-boggling that they were even capable of flying… there’s probably very little i wouldn’t believe about them considering how unbelievable what’s known to be true already is…)

    On eagles, has Darren covered Washington’s (aka Audubon’s eagle)? A cryptid, inland-living Haliaeetus with a >3m wingspan, drawn and painted by a world-renowned ornithologist and illustrator with detail to convincingly place it in a known genus but no known species, from specimens he handled himself…

31. #31 DCN

    October 10, 2008

    When hunting a wolf, the golden eagle overtakes and swoops down on the fleeting animal, gripping the mask with one foot, in order to prevent the wolf biting, and the back with the other. The great bird then does its best to bring its two feet closer together and thus break the animal’s spine, but with a wolf this is seldom possible, and the eagle is content to hold it until the arrival of its master. It is said that if an eagle several times misses its stoop it becomes so angry that it will sometimes fly at a man. On one occasion an eagle swooped at its master because he was wearing a cap of fox fur. The eagle’s talons pierced an artery and the man died.

    - Seton Gordon, “The Golden Eagle: King of Birds”

32. #32 David Marjanovi?

    October 11, 2008

    Is there evidence that pterosaurs *were* fully homeothermic?

    Well, the smaller ones probably couldn’t have flown otherwise. Then there’s the fur, and then there’s the pneumatic skeleton that very strongly suggests a bird-style respiration system (even bats don’t have air-filled bones).

33. #33 August Pamplona

    October 11, 2008

    There was a nature series in Spain decades ago which prominently featured an eagle carrying off a wild goat in the opening credits. This was really the series which started the genre of wildlife documentaries on Spanish television, I suspect. Unfortunately, Felix Rodriguez de la Fuente was less than kosher with the ways he obtained his footage at times. In this case, I believe that the goat had been maimed to obtain the footage and the eagle filmed was a trained eagle (Dr. Felix Rodriguez de la Fuente was a master falconer).

    Here’s a video clip which shows the event from which that opening sequence was drawn:
    http://www.youtube.com/watch?v=rKA0UlMfmwM

34. #34 August Pamplona

    October 11, 2008

    So basically this boils down to a question of the load-carrying capacity of African and European eagles. Are there any predatory swallows involved?

    African or European?

35. #35 Ricardo

    October 11, 2008

    http://es.youtube.com/watch?v=Yz7FFlFy8eM

    This is some footage of a spanish wildlife series by Rodriguez de la Fuente. He was quite a figure here in Spain, don´t know how much outside impact he had… Anyway, you can see some bastard eagles throwing goats off some cliffs.

    Wonderful blog, I´m becoming quite a fan…

36. #36 Darren Naish

    October 11, 2008

    Thanks for comments. Féliz Rodríguez de la Fuente’s footage of Golden eagles killing goat kids by pulling them off a cliff was covered previously on Tet Zoo here. While I described the footage as ‘faked’, the footage showing the killing was most certainly not faked (though it was staged).

37. #37 Jerzy

    October 11, 2008

    If you mean some winged animal using wings to warm itself – its a bit tricky. In flight, air passing the wing cools the animal faster than it warmed itself before.

    It would be possible with animal which flies very rarely (like gliding lizard Draco volans).

38. #38 Brian Schmidt

    October 11, 2008

    I’ve done a fair amount of solo mountaineering in Alaskan golden eagle territory and I pay attention to mountaineering literature, and I’ve never heard of eagles attempting to scare climbers into falling.

    Not saying it’s never happened, but it would have to be extremely rare. I wonder if what might look like that behavior may actually be defense of an unobserved nest, fledgling, or kill site.

    But, I also know of a building maintenance man in California who had to armor himself with with a garbage can lid and a broom, and do battle with a peregrine falcon pair when he had to get up on his building’s roof.

39. #39 Darren Naish

    October 12, 2008

    Brian: the ‘attempting to scare climbers into falling’ stuff concerned lammergeiers, not golden eagles.

40. #40 Mark Lees

    October 13, 2008

    “African or European? ” – I don’t know that – aaaarrrrgggggg

    Started off as a nice sensible post about raptors picking on dogs/cows/random mammals and now it’s just got silly.

    I had nothing useful to contribute to this interesting thread, so rather than have the sense to say nothing I latched on to the Monty Python subtheme.

41. #41 DDeden

    October 13, 2008

    OT: Cold blooded critters (fish, N mole rat) don’t sun themselves, can’t handle strong sunlight. Cool/warm blooded critters (crocs, snakes, black vultures) do. Large fliers are dark, except seasonal migrants (cranes). Early gliding birds & pterosaurs on cliffs and canopy were sun-warmed, helped their lift/glide, their dark wings didn’t sweat and lacked fur/feathers. As homeothermy improved with high energy diet, less need for sunlight, more need to retain internal warmth, so down developed on torso, then to wings, then flight feathers and smaller-lighter tails/wings.

    Flapping wings was for cooling/aeration, just like insect wings, which developed into partial flight. Both coral and sloths have symbiont algae which photosynthesize, but that wasn’t my point. Top of canopy was safe for early birds/pterosaurs, except for strong wind; thin twigs couldn’t support big snakes or reptiles (which tend to attack eggs), so skeletal lightness and tail reduction (replaced with long feathers) was selected for.

42. #42 Stevo Darkly

    October 13, 2008

    There was a nature series in Spain decades ago which prominently featured an eagle carrying off a wild goat in the opening credits. … While I described the footage as ‘faked’, the footage showing the killing was most certainly not faked (though it was staged).

    Nooo-one expects a Spanish eagle fiction!

43. #43 Stevo Darkly

    October 13, 2008

    When attacking unusually large prey, I imagine that golden eagles rely as much on the “psychological” aspects of shock and terror in order to overcome their quarry, as much as their physical strength. Especially when trying to startle prey into losing their mountainside footing, as mentioned above.

    In other words, their chief weapon is surprise.

    Surprise and fear.

    Their two main weapons are surprise. And fear. And … I’ll come in again.

44. #44 Brian Schmidt

    October 13, 2008

    “‘attempting to scare climbers into falling’ stuff concerned lammergeiers,…”

    OK. I don’t really follow European mountaineering literature, so maybe they’ve reported the behavior. If they haven’t, that again suggests it has to be extremely rare or a misinterpretation of their behavior.

45. #45 David Marjanovi?

    October 13, 2008

    Cold blooded critters (fish, N mole rat) don’t sun themselves, can’t handle strong sunlight.

    But not because they’re cold-blooded! Naked mole rats would get sunburnt — and they aren’t cold-blooded, they are intermediate! –, and fish can’t risk drying out.

    Cool/warm blooded critters (crocs, snakes, black vultures) do.

    You invent terms and categories for no reason. Crocs and snakes are cold-blooded (ectothermic, poikilothermic, bradymetabolic and bradyaerobic), all birds are warm-blooded (endothermic, homeothermic, tachymetabolic and tachyaerobic).

    Large fliers are dark, except seasonal migrants (cranes).

    And swans, and most albatrosses…

    Early gliding birds & pterosaurs on cliffs and canopy

    Pterosaurs perhaps, but birds did not go through a phase where they were strongly adapted to climbing, and there’s no evidence for a gliding phase in bird origins either.

    were sun-warmed,

    No. Dinosaurs in general were warm-blooded. That logically includes the ancestors of birds!

    helped their lift/glide,

    How?

    their dark wings didn’t sweat and lacked fur/feathers.

    Bird wings consist only of feathers. Without feathers, a bird arm is not a wing.

    As homeothermy improved with high energy diet,

    This speculation is unnecessary for birds, because their ancestors were already homeothermic.

    less need for sunlight, more need to retain internal warmth, so down developed on torso, then to wings, then flight feathers and smaller-lighter tails/wings.

    Are you completely unaware of Sinosauropteryx???

    Flapping wings was for cooling/aeration, just like insect wings, which developed into partial flight.

    Why would they need that much cooling — and how does that work in animals that don’t sweat?

    Besides, insect wings are derived from tracheal gills that were most likely used as fins for swimming and then for moving forward while standing on top of the water — something that stoneflies still do.

    Both coral and sloths have symbiont algae which photosynthesize, but that wasn’t my point.

    ARGH!!!

    The symbionts of corals are intracellular and actually feed the coral. The symbionts of sloths live in their hair and do nothing for the sloth except making it green (camouflage)!!!

    Top of canopy was safe for early birds/pterosaurs,

    Early birds were not on top of any canopy.

    thin twigs couldn’t support big snakes or reptiles (which tend to attack eggs),

    Snakes have only existed for the last 100 or so million years, and terrestrial snakes for even less. We have no idea where any pterosaur nested; given the poor climbing and flight abilities of animals like Archaeopteryx, it’s doubtful that they nested in trees either.

    so skeletal lightness and tail reduction (replaced with long feathers) was selected for.

    Then why did the latter take the pterosaurs so long, while the former is common to all saurischians?

    You should get out less and read more. You have a lot to learn.

46. #46 Christopher Taylor

    October 13, 2008

    Besides, insect wings are derived from tracheal gills that were most likely used as fins for swimming and then for moving forward while standing on top of the water — something that stoneflies still do.

    The origin of wings in insects is looking a lot more iffy in recent years than it was not so long ago, and the paranotal ghost has begun to rear its head. The idea that surface-skimming could have given rise to flight has taken a pretty significant hit with the increasing establishment that stoneflies are not a particularly basal lineage within insects, and those stoneflies that exhibit surface-skimming are not necessarily basal within stoneflies. This is not to say that surface-skimming was automatically not a stage in the evolution of flight, but even if it was, surface-skimming in modern taxa is a more derived feature rather than being retained from the pre-flight ancestor.

    Of the four basalmost major pterygote lineages, living Ephemeroptera and Odonatoptera have aquatic nymphs while basal Neoptera and Palaeodictyopteroidea probably had terrestrial nymphs. The most widely supported phylogeny for insects unites Odonatoptera and Neoptera to the exclusion of Ephemeroptera. It’s an open question at present whether the aquatic nymphs of Ephemeroptera and Odonatoptera represent a shared plesiomorphy of the pterygote ancestor or an independent derivation in the separate lineages. The exceedingly poor fossil record of super-basal pterygotes may suggest a terrestrial rather than aquatic ancestry for the group, but as an argument from negative evidence it’s pretty weak.

    It has been shown developmentally that the genes active in wing development are also those involved in crustacean gill development. However, there are enough examples of gene processes being convergently co-opted in separate lineages (for instance, the same genes are involved in arthropod and chordate limb patterning despite the common ancestor of these groups almost certainly not having limbs) that this does not completely seal the deal.

47. #47 DDeden

    October 14, 2008

    OT: What’s the chance that some type of (basal) coastal pterosaurs evolved eventually into birds? Zero?

    I’m thinking that theropods and Aves developed from a basal flighted pterosaur with primitive feather-scales which became islanded (with no ground predators) and (as typical) reduced flight, some becoming flightless partly-ratite-like (Theropods) while others maintained gliding, then some re-evolving flight (early Aves) due to new niche opportunities. All of these could have had a variety of scale-feather combinations. Some could have nested in canopy, others on sea cliffs, others in tree hollows, others on soil, or sandy beaches. (Thinking of New Zealand and Papua bird variety.)

48. #48 johannes

    October 14, 2008

    > I’m thinking that theropods and Aves
    > developed from a basal flighted pterosaur
    > with primitive feather-scales

    That’s a just-so story. Reminds me of Sera’s idea that elephants, sirenians and desmostylians were late surviving dicynodonts – all other mammals are, of course, amphisbaenids .

49. #49 Dr Jack

    October 14, 2008

    DDeden:it is fun to speculate, but you do not seem to understand how science works. We do not come up with an idea and then look for evidence – instead we look at evidence and then propose an idea (an hypothesis) that might explain it. There is much data on the early history of pterosaurs and birds, you must look in detail at this BEFORE speculating on scenarios about their evolution.And none of the evidences lean towards your suggestions by the way.

50. #50 Chris Clark

    October 14, 2008

    Would an eagle always need to lift an object it was carrying into the sky? Aircraft flying very close to the ground get extra lift from an sort of air cushion; how directly this applies to a flapping wing I don’t know, but an eagle might move a heavy body some distance by ground skimming.

51. #51 DDeden

    October 14, 2008

    OT: Note the pattern, then the conjecture:

    1) Running biped short-forelimbed short-tailed Ostriches derived from flying long-forelimbed short-tailed ancestors.

    2) Running biped short-forelimbed long-tailed Theropods derived from flying/gliding long-forelimbed long-tailed ancestors.

    A flying predator attacking hornless prey from above, would eventually select for prey with horns, which would then select for ground dwelling predators which attack horned prey from below to attack the soft parts (throat). Theropods share traits with birds because they derive from flying/gliding/climbing predatorial ancestors, not sauropod-like ancestors, I’d think. It’s not so much an idea, as it is pattern recognition.

52. #52 Stevo Darkly

    October 14, 2008

    Chris Clark — Interesting idea; you are referring to what’s called “ground effect” or “in ground effect” — there is a bit about it here: http://www.wigetworks.com/ww_tech.htm

    Googling +birds +”in ground effect” turned up some statements that some baby birds use this effect when learning to fly, and an article (not available to me) speculating that Archaeopteryx was a habitual “in ground effect” flier. So birds can use this effect, but it limits them to about half a wingspan above the ground. Flying long distances this way is also easier if the surface beneath is relatively flat and smooth; the effect will be lost whenever the distance between the bird and the surface gets too big. So it’s easier to use above water or a very flat land surface; not so practical for hilly terrain.

53. #53 Steve Bodio

    October 14, 2008

    Seton Gordon’s description of wolf eagles is derived from 19th century traveler’s tales like Atkinson’s and is a bit overdone. The eagles I saw in Mongolia (and the ones in eastern Europe who routinely kill roe deer) are almost placid with their handlers and wouldn’t “turn on” them. I doubt they have to break wolves’ necks– the tissue damage and blood loss from their strike is astonishing. They do try to control the muzzles of wolves and foxes.

    All Kazakh eaglers wear fox- skin headgear in the winter and I doubt they would if it were dangerous. It would be selected against to say the least (;-)) The birds are worked with tazi dogs in Kazakhstan and are perfectly capable of distinguishing what is quarry, as are most trained hunting birds.

    Goldens EASILY kill animals the size of roe and North American pronghorn– the second is almost routine in winter. They don’t have to carry them- they feed in place.

54. #54 Graham King

    October 19, 2008

    Brian Schmidt said
    

    I’ve done a fair amount of solo mountaineering in Alaskan golden eagle territory and I pay attention to mountaineering literature, and I’ve never heard of eagles attempting to scare climbers into falling.

    That might be because the eagles try it on humans only rarely, but whenever the eagles do try it, they succeed. Those might be the solo mountaineers who never returned to tell their tale.

    I hope that it is not so.

    I’ve read that in India some villagers in tiger territory wear eyed masks on the back of their head to deter tiger attack (tigers reputedly preferring to attack humans only from behind). Perhaps there is some gear or garb devisable for climbers to deter eagle attack? (Adaptable too for livestock protection?)

55. #55 David Marjanovi?

    October 21, 2008

    What’s the chance that some type of (basal) coastal pterosaurs evolved eventually into birds? Zero?

    Of course. If you were halfway familiar with vertebrate anatomy, you’d understand why. I’ll say it again: Read more. Read lots more. And then come back. You have no idea how much evidence against your speculations exists.

    It’s not so much an idea, as it is pattern recognition.

    It is an inductive inference — an idea.

56. #56 DDeden

    October 23, 2008

    OT: Ok, now I got it, I said ‘basal pterosaurs’ but I meant ‘arboreal archosaurs’ (probably coastal) from which both birds and pterosaurs derived, IMO.

57. #57 David Marjanovi?

    October 24, 2008

    I meant ‘arboreal archosaurs’ (probably coastal) from which both birds and pterosaurs derived, IMO.

    And there we have your problem: you have yet to learn that you simply can’t talk about a topic if you don’t know anything about it.

    Birds and pterosaurs are not close relatives at all. The birds are closer to Triceratops than to the pterosaurs. We know quite precisely what the closest known relatives of the birds are, and those animals are neither arboreal nor coastal nor basal archosaurs. You can’t simply act as if knowledge didn’t exist just because it happens not to have reached your eyes yet.

58. #58 Phil

    October 24, 2008

    Darren, you may have already seen Scott Maruna’s evidence for “Avian Abduction” as written up here: http://biofort.blogspot.com/2008/01/avian-abuctions-back-in-news.html

    He also collected a series of newspaper accounts of eagles attacking children, one of which ended with the death of an infant whose skull was opened and the brains eaten before the eagle could be driven away.

59. #59 Dartian

    October 31, 2008

    Speaking of vultures attacking humans:

    Griffon vulture attacks Ipswich woman (at a zoo in the Canary islands, not in the wild).