I agree with Mike that the big examples of these would take small dinosaurs if they got the opportunity. However the oft floated idea that these were regularly taking large dinosaurs is for me rather unlikely. The shape of the head is much closer to things like the modern gharial and false gharial (a long and thin snout) that primarily take fish and don't often go for big terrestrial animals (compare them to big crocs and gators).
Posts by David Hone
Posts found [ 1 to 50 of 1,218 ]
Dinosaurs were, on average, at adult size pretty big (over a ton). It's a bit of a recent myth that they were mostly small.
Paul has written in to say this is actually a wasp-mimic and is in fact a form of crane fly.
"This Fly is in the family Tipulidae,and these are called
Crane flies. This one is a wasp mimic,meaning it masquerades as a wasp so
that insectivores will stay away from it. It's scientific name is Ctenophora
elegans. It neither bites nor stings."
There are lots of great fossil sites ina dn around Los Angeles (La brea, various fossil shwales on thew coast) but there's no exposed rocks of a suitable age for the Mesozoic dinosaurs in and around LA. Still, they almost certainly lived there, dinosaurs had a truly global distribution and any land mass or island would have had dinosaurs on it.
That is only one definition of about 15 that are in common use. Biologists use different definitions for different sitautions - being capable or reproducing is not much to go on when dealing with fossils or asexual organisms and plants for example. The reason we have so many is that life is very variable and the concept of a species is always going to be somewhat artifical - individuals and lineages are not discreet entities like atoms, but are part of an ever evolving chain. None of the individuals that make up lions as a species were alive 100 yeas ago and none of the ones alive now will be around in a hundred years but they are all part of the same species. Speciation can take time and species can merge into one another or are not yet properly split so we need apprpraite definitions to deal with this pheonmeon.
It was either neither or both, depending on how you phrase it. Like almost all carnivores it would have hunted prey and taken what it could find of already dead animals. We actually have excellent direct evidence of both hunting and sacvenging from the fossil reocrd, so it's not an either-or case.
They look like sponges. Although most we are familiar with are from coral reefs, there are actually lots of cold water and deep water sponges including plenty around Scotland and the north sea generally. They are about the right size and shape and the general texture and patterns are reasonable too, so I'd plump for a sponge.
I think it's fair to say that the palaeontological community as a whole is extremely sceptical of every part of the 'Triassic Kraken' concept and none of the arguments are very convincing at all.
Well in the short term rapid climate change is likely to kill a lot of species if they cannot adapt well to the changing conditions. However, long term yes, if the temperature remains both stable and high, it is the right conditions for large reptiles to evolve (especially things like snakes) though of course what else is happening to the environment through human action could easily stop it happening.
This is something we actually know almost nothing about. There's a decent number of hyoids out there but they've only been looked at once even semi-seriously and no one has looked at muscle attachments, size etc. As it happens I'm helping a student who is looking at this area, so watch this space.
The plant is certainly not suffering in the sense that it doens't 'know' what has happened - it won't be disappointed or anything like that. It may not be good for the plant to waste energy closing wihout having something to feed on, but that's a different story.
Paul has written in correctly identifying this as a mole cricket - they're rather common in parts of China.
Depending on quite what you read, it might very well relate to some current research I am doing to pterosaur growth! There does appear to be some differences between species but in general they do indeed seem to be fairly isometric, but this is becuase unlike say birds or mammals (including bats), juvenile pterosaurs could fly and so young animals had simialr proportions to adults which would facilitate this.
These are fictional animals and do not behave like real creatures would. These animals would not have been this fast or agile, and it's also extremely unlikely they would ever have had a stand-up fight even if they were soemhow thrown together.
Velociraptor as a real animal was small (under 2 m long, under 1 m tall). The film version was in part fictional exaggeration and part conflation of Velociratpor with Deinonychus and a desire to have a name that sounded good.
Natural seleciton also needs a selective pressure to change things - sitting badly might give you problems but it won't stop you having a full life and having kids etc. so natural selection can't change you to adapt to this as there's no advantage to sitting better.
I think this is actually a weasel skull - small mustelind do have this very long back part of the skull and it fits with the carnivorous teeth in the jaws that are quite unlike those of rodents. They are well within the prey size range of a decent sized owl but it's quite a catch!
I don't know of any technial terms other than 'retractable'. Most cats and a few other things (like some badgers) can partially or fully retract the claws so it's not a big list anyway.
Well first off this is posted in 'birds' and these animal were flying reptiles, not birds. Secondly, although in common use, the term 'pterdactyl' is incorrect and you should use 'pterosaur'. Thirdly, I'm afriad this question is so general as to be redundant, you might as well ask about the envirnments that mammals live in or birds - there were many ptersaur species and they lived around coasts, over oceans, inland, on plains and in forests and probably pretty much everywhere.
Paul has mailed us to say:
"These are not cockroaches. They are True bugs of the insect order Hemiptera. In the second picture, you can see the Cris-cross wing pattern typical of this order of
insects. The second picture is fuzzy, but I think they are Boxelder bugs."
I agree these are not cockroaches or indeed anything to worry about too much.
Some things can happen almost instantaneously - plants often spontaneously double their number of chromosomes when reproducting leading to offspring with twice the normal DNA. This means that they can't normally breed back with the parent species and may have large cells and be especially large themselves. In short, a single generation may be enough in some circumstances.
Oddly enough this question has just come up in a discussion between some colleagues of mine, and the general conclusion was 'probably not' as they seem to lack the joint mobility to allow them to move around on land at all.
Based on the feathers and the size I'd guess it could be a bittern, but that might be a long shat as they're fairly rare.
It really depends what species you have - 'parakeet' is a bit generic and doens't narrow it down much. I would imagine one male might well pair with the female, but I suggest you speak to a professional breeder for advice.
No one has done this work specifically (in fact I'm not sure there's a good femoral head and axcetabulum of an adult Deinonychus anyway) and in any case range of motion studies in extinct taxa are fraught with problems as so much of the key informnation (like ligaments) simply isn't there. What would would predict from bones alone is often not a good match for what we know animals can and can't do, so it's of limited value. I would say your picture looks reasonable and that's about the best available.
Well you said you're not here to ask my opinion and then finish with 'what do you say' which rather does sound like asking for an opinion...
First off, you're really massively over simplifying things - finding a meal is not jsut about risk, it's about the potential souces of food, where they are, what other food might be around, what risks, what other carnivores, the evnivornment (and then times of day or seasons) etc. and it's all different for species and even indiviudlas at various times. Some lion populations hunt a lot, some scavenge a lot, cheetahs very rarely scavenge, vultures rely on it.
We know that both Tyrannosaurus and Velociraptor were both predators and scavengers - we have good fossil evidence for both ehaviours in both taxa (I actually published a couple of papers on the subject myself). Beyond that, it's hard to say much realistically about proportions of activities as the fossil evidence is not there and there's nothing in their anatomy or basica patterns that really suggest one over the other for either. That's all we know.
Some small pterosaurs, most notably the anurognathids certainly hunted insects and I'm sure various other juveniles and some adults did too. All the early pterosaurs that we know of were at some level carnivorous and many ate fish, though other things were probably also on the menu. I actually wrote a paper about it just this year!
The first dinosaurs date back to around 240 million years ago and the main extinction event was 65 million years ago, though of course birds are still alive today and are living dinosaurs.
Paul has e-mailed in with an identification as a Black witch moth. It's scientific
name is Ascalapha odorata. Our thanks to him.
I'm farily sure it's not a fossil bone - actually looks rather like worn flint. both natural and worn bones have very distinct patterns and textures and I can see none of that here, and if it was a bone, the walls are far, far too thin and simple.
Happily for you, I've written a guide to exactly this problem! :) Hope this helps and good luck.
I'm not 100% convinced it's a fossil, but my best guess is that it is a section through something like a coral or a sponge, hence the various rings (i.e. these are cut through tubes).
Depending on quite where you live and the local conditions it's perfectly possible. Larger things like the head of the femur might well survive, but it would be easy for you to miss this and it would likely have lost some shape. There's probably little if anything there for you to find.
Huge numbers of birds do this, most obviously various ducks and waterfowl.
I have no idea what difference in head posture you are referring to - I'm not aware of any apparent differences between the two so I'm at a loss to answer this.
Well we've not found every species for every fossil locality and envirnment (and probably never will). While these two genera might never have exactly overlapped, it's possible they they did and certainly near relatives of each are found together in other places.
There are certainly specimens of young animals that are identified as belonging to Tyrannosaurus with some confidence. There are other specimens that have been identified as 'merely' young Tyrannosaurus or as a new small genus called Nanontyrannus. However most researchers I know are happy with the idea that this genus is not valid and all these things are younger specimens of Tyrannosaurus.
Well potentially - most carnivores will hunt most other herbivores at least at some point in their lives. However, we have no direct evidence of any intereactions between them (bitten bones, stomach contents etc.).
They are raised up at least a bit (they don't ust drag themselves along the ground) but they are very low-slung and cannot raide themselves into an upright posture with the legs under the body as with mammals or the 'high walk' of crocodiles.
I really can't tell much from the photo, a better close-up would help enourmously. You'd need to submit a new question though.
Wow, that's an odd one. However my guess is that it's a fish of some description as they have a number of these super thin and smooth bones. Fish have really complex head swith tons of small and odd shaped bones and I think this is most likely some part of the skull, but it could be the base of one of the fins.
It's clearly worn from being in the water, but I agree with David that it's probably a finger / toe bone of something large and mammalian (like a deer, cow, pig etc.).
Generally not very well. If yo remove even a few major primary feathers (from the tips of the wings) most birds will struggle. They will probably still get airbourne and not look too impinged upon, but it will take much more effort than normal so they will be flying slower, be less able to turn and will tire. Take out most of those from both sides and they probably can't take off (hence clipping wing feathers of pet birds to stop them flying away).
The term you want is 'gastrolith'. Only a few dinosaurs had them, and they are generally only associated with smaller plant eating dinosaurs (as with many modern herbivorous birds). They can be told as they are generally found in a mass inside what would have been the dinosaur's chest cavity and they are typcially very smooth (becuase they've been rattling around, possibly with some acid) and tend to be of an unusual geology since they will have been picked up somewhere else by the animal.
This is the same person who has been onto us before arguing that birds evolved from pterosaurs. He's not worth arguing with.
While most new species historically were given names in Latin or Greek, many have roots in other languages (and especially those that are named for places which often are locla names in local languages). This has been an increasing trend and one can find dinosaurs and fossil reptiles names that use a huge number of local languages (Quetzalcoatlus, Tsaagan, Nanaqsaurus, Nqwebsaurus). With so many dinosaurs coming from China, it's little surprise they often have names with roots in Chinese, though again, much of this are simply place names - Zhuchengsaurs, Liaoningsaurus, Linheraptor, Jeholornis. Hope this helps.
Well no quite, they *walk* on two toes on each foot, but there are fur present on each foot. You can see the nubs of the toenails either side of the main toes (just as in a cow).
yes Ornithocheirus does have an expansion to both the upper and lower jaws. These are part of the skull, but would have been covered in skin and perhaps even part of the beak as well which would make them larger in life.