Dinosaur egg?

[Tumbleweeds]

My neighbor just stopped by with this little jewel - it certainly looks like it is to me, but can anyone give me some tips as to how to confirm if it really is a Dinosaur egg? Size wise it's about that of a chicken egg. The surface is really intriguing, kind of leather like? Comparing it to google images it sure looks very similar, but how to be sure? Thanks for your help.

[tyrantqueen]

This might sound dumb, but how do you know it's not a pebble? One of those tumble rocks or whatever they're called

[SBell]

It would be good to know where it came from, and what the surrounding rocks, etc were like.

But it looks more like a weathered, round rock. The material almost looks like basalt or something. From a photo of course.

[Tumbleweeds]

The scan isn't very good, sorry 'bout that. It flattens it out. Holding it though, it has a lot of heft for it's size and it is shaped very much like a large chicken egg. If you were holding a really heavy black chicken egg with a leathery like surface that's what this thing is like. It's surface is unlike a river rock, they're generally smoother than this thing. It's from southern Colorado. It's not too difficult to find fossils around here, though I do not know the specific details of the area it was found.

I realize it could be anything really, including a funky looking pebble, but is there a way to tell other than having it x-rayed or something?

[amargasaurus cazaui]

 A definitive solid yes or no with just a few images is somewhat impossible to give. My suggestion if you want a solid yes or no would be take it to a museum like the Denver Museum of Nature and Science where there are people working in the prep lab that could look it over and give  a more solid examination.
  Having said that, I do offer that the general shape is not what would normally be considered commonly for an egg, for a rather simple reason. Most dinosaur eggs that are found themselves do not look like eggs either. Generally there are quite a few factors that come into play with any egg to determine how it preserves. Was it intact when it was buried? Was it allowed to crack and allow infill to equalize the pressure around it as it was buried? What sort of material was it preserved in? All of these factors are important to the final egg fossil. The end result is you have an outside shell, which should be quite obvious, not just from surface texture but from multiple cracks and breaks in the shell allowing you to see the edges of the Shell. Most dinosaur eggs have a shell composed of at least two layers which under slight magnification are quite obvious, one of which is made of vertical shafts . The internal portion of the egg should likely be the color of the surrounding matrix it is found within. It is generally only a cast of the empty inside of an egg. Many people presume you can ex-ray an egg and get answers...but even that is reliant on an enormous number of factors all aligning perfectly to give any visible trace to be found. If you can conceptualize the egg with a chick within....by the time solid bones begin forming the chick is  almost ready to hatch. There is a small window during which there are bones which might fossilize before the chick will emerge during which it would have to perish, somehow avoid being consumed, become fossilized with the bones within the egg still.
   A further tell when checking for a possible egg is compression. As the eggs become buried deeper and deeper, either they smash completley flat, or at least compress into a  shape quite different than it began as. Seldom does an egg preserve looking just like an egg...and it generally requires that a small area of the shell cracks or breaks allowing the matrix to infill and equalize pressures before the egg pancakes underground from the sheer weight of the layers above.
  I also agree with the previous person who stated the material looks like a granite or some other form of non sedimentary material. But further and even more telling, the entire piece seems composed of the same material...there is no outer shell, no inner fill and no difference in the entire piece to suggest egg, shell, or infill for that matter.
  A final thing that seems to somewhat call into question the idea of being a dinosaur egg...in general most of them range in size from basketball sized to eighteen inch long elongated eggs....and there are a few species that produce eggs this small.....however generally when a smaller egg turns up, I generally see an identification suggested for it more in line with snake egg, or turtle if indeed it is an egg at all. The size here is not an impossible thing, but given all of the other indicators it seems another factor not supportive of this being at least a dinosaur egg.
   Just looking at a picture and going by what I see, I propose a different answer for why your stone looks river tumbled, appears ground and yet is not the same as most river tumbled stones. And I also state that it is a guess just looking at some pictures...and an opinion and nothing more...but I propose that rather than river tumbling your stone is in fact a gastrolith. The fact the surfaces are all ground, but the grinding is only on surface areas and does not follow into seams or cracks further enforces that identification.
  I can also suggest you view my thread within this forum regarding dinosaur eggs. I own four specimens from four likely seperate species and the four have been confirmed by a leading paleontologist on the topic as being indeed actual dinosaur eggs, and further two of them have been given a likely identification to possible genus. You can get an idea of the size, shape, patterning and overall "look" of eggs from the ones I have posted.Here is  a link to my thread if you like
http://dinotoyblog.com/forum/index.php?topic=453.0
   

[Tumbleweeds]

Thank you amargasaurus cazaui! Very informative and much appreciated. I was going to try to take some pictures of it, rather than the scan, but I realize it's tough to tell what it is by pictures. The Denver museum is about 150 miles from me, but the Dinosaur Resource Center in Woodland Park is much closer and I was wanting to go to it again anyway. They have a lab so someone there may know. If I do get some pics I'll post anyway, just as a FYI. And I'll report back when I find out what it is.
Thanks again.

[Dinoguy2]

This looks to me like a weathered lava rock. Dinosaur eggs were not shaped like chicken eggs, they tended to be round, like basketballs, or long oval shapes. The surface texture of an egg would have lots of tiny bumps, like a football.

[amargasaurus cazaui]

This looks to me like a weathered lava rock. Dinosaur eggs were not shaped like chicken eggs, they tended to be round, like basketballs, or long oval shapes. The surface texture of an egg would have lots of tiny bumps, like a football.

The last comment there is a bit slippery and tricky because not all eggs are the same. Any egg under magnification will reveal ornamentational partterns to the surface wether a pattern of raised barlike structures or dots that might be either close together as suggested of a football or wildly irregularly spaced. The ornamentation itself can also vary widely in size......
  By example theropod eggs do look quite as suggested...pebbly almost or similar to a footballs pebbled surface. Duckbill and segnosaur eggs look smoother for a few reasons..the first being the ornamentation is much flatter in general, and the second because it tends to hold the matrix within it creating a more even or flat look.
   Ornamentation is a much trickier thing than shape, size etc. It is often used to identify various genus of eggs that appear similar otherwise.....if you feel it would benefit you I can post you close up shots of at last seven different types of oranmentational patterns so you can see the variance and if you feel any of it matches your object.
   Even then it is only half the story as a cross section of the shell, how thick the layers are, how they are patterend and what crystal formations are present are much more indicative of what kind of egg it is.
   Eggs are by their very nature tricky and elusive in many ways. Most eggs are identified independently of the dinosaur that may have laid it...because unless you have an egg from that locale with matching size, shape, ornamentation and thickness of shell....with an embryonic within it, you cannot attempt a specific identification of the animal that laid it. Or the short way to say it...is you might feel you can extrapolate what species laid it...but what if the responsible dinosaur is as yet undiscovered itself? Which also means you might find an egg this small...or this shape..and it could easily match an as yet unknown type of dinosaur. Most of the dinosaur eggs we do have generally belong to one of the shapes suggested...elongoolithus or spheroolithus, however there are far more shapes known than just the two.

  This is why I stated it is all but impossible based on a few pictures to give a solid, written in rock identification. Most of the necessary factors to suggest egg are in fact not there , but are more directly related to lack of cracks in shell, lack of differentation suggestive of a shell layer and the outward patterning is not consistent with most known types of eggs. Even with that comment you have to be careful because sometimes eggs themselvs can be tossed and turned in water for a long time before found and will demonstrate shell texture underneath tumbling action. The material itself looks more like a naturally occurring rock than sedimentary as I said previously however. I do again repeat my suspicion this is a gastrolith stone given the wear pattern.

[LophoLeeVT]

wow it looks like a hysilophodont egg~

[stargatedalek]

From the few I've seen in person I'd say that this is probably not a dinosaur egg, and that if it is it's probably a bird.

[Plasticbeast95]

looks like a rounded-off stone, like you would find on a river bead.