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- Past hour
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Getting up there myself enough to start shouting at kids to get off my lawn.
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Interesting topic. I’m generally skeptical of conclusions from a single study that overturn years of understanding. It takes time for them to be debated and validated. I’m sure the arguments are already forming in the shark-paleo circles.
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And a nice one showing some of the interesting texture. See this other topic: Cheers. -Ken
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I just get a bit grumpy in my old age sometimes
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The condition may make it hard to identify for certain, especially since incisor teeth are often similar in different species, but deer incisor seems likely to me.
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Member Of The Month - Time for a change? Please give your opinion.
FranzBernhard replied to Fossildude19's topic in Member of the Month
About 50% of all MotM (ca. 189 in total until the end of 2023) have posted in 2024. Just an approximation ;-) Franz Bernhard -
I would like to see both sides and inside as well. Crab remains possible at this time. The exotic color is one reason to wonder
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My main interest is fossil fish, but you will also find some other vertebrates like amphibians, mammals, reptiles and birds here in this album: Fossils from Solnhofen, Messel, Holzmaden, Liaoning, Bergisch Gladbach, Green River, Linton, Mazon Creek, Monte Bolca, Fiume Marecchia.....and other places around the world.
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Peace River 4/24/2024 (lots of 4s)
MuckyBottles replied to Shellseeker's topic in Fossil Hunting Trips
Great finds! Ill be out today.. -
Some more in focus, up close pictures may be required. Cropped and brightened:
- Today
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Member Of The Month - Time for a change? Please give your opinion.
Fossildude19 replied to Fossildude19's topic in Member of the Month
@Top Trilo Alex, Guess I am more of a numbers, guy. How many have been awarded a MotM, and how many of THOSE people are still active right now?- 129 replies
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Oxynotus joined the community -
The OP has not logged in since posting this, so may respond once logged in again. That said, I interpret the benefit of even non-responses differently; for every person who posts an item, there may be five or more others who have something similar, so our replies become educational and informative to others -- even and especially when we show our thought process. We lead by example.
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A picture of it out of the plastic bag would be ideal but it does look like a Charcharodon hastalis lower tooth.
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Piece of what I believe is reptile rib bone from Big Brook, NJ. Bone fibers are very dense - any chance it could be dinosaur?
pachy-pleuro-whatnot-odon replied to TRexEliot's topic in Fossil ID
One of the problems faced by aquatic animals is to achieve neutral buoyancy, so that they neither sink to the sea floor, nor float to the top of the ocean. To do this they increase the weight of their bones. For this, there are two strategies, either increasing the thickness of the bone cortex in a process called pachyostosis, or increasing the density of bone fibre in a process known as osteosclerosis. If both conditions occur simultaneously, this is known as pachyosteosclerosis, which is what's seen in most secondarily aquatic creatures. The bone being spongier would allow for it to be lighter, as there's more room for air, therefore making it less likely to belong to a secondarily aquatic creature and more likely to be a larger terrestrial animal, who often incorporates air pockets in their bones to lighten them. This is taken to the extreme in animals like pterosaur - which bones are thin-walled and almost completely hollow - and sauropods - which have a lot of air sacks in their bones. The latter is where Camerasaurus gets its name... -
Member Of The Month - Time for a change? Please give your opinion.
rocket replied to Fossildude19's topic in Member of the Month
looks like that most of the MOTM are still active members -
I guess the OP is at a loss for words, as many of these first posters in the ID section are. Sometimes I ask myself why I bother, but then of course there are just as many polite ones who react courteously.
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Another crab hunt in the Britton Shale of Dallas 4/24/24
Gcurtis45 posted a topic in Fossil Hunting Trips
After yesterday’s (4/23/24) hunt I decided to go back today after work. Let me tell you all, it did not disappoint! In total I found ~36 fossil decapods. 23 crabs, 12 shrimp, and “1” lobster. This brings my total cont from today and yesterday to ~49 decapod fossils. Also to note is the scale of the cutting mat in the background, every square is 1/2 inch for scale In regards to the “one” lobster it is in two pieces that might or might not belong to each other, they were found in close proximity to one another and have similar mineralization color and the size of the tail section could fit a lobster of this size. This specimen looks most like Linuparus grimmeri, I have two other examples of this species form much higher in the Britton shale, one found by me and one by my father, another note on this specimen is the size of the mandibles on the under side. Next up on the list is the best preserved and looking shrimp fossil of the day, I don’t have an ID on these guys yet, if anyone has any ideas please let me know. In all the only thing missing is the tail fan, it still has its head, tail, and even some leges and its two claws/pincers intact, in order shown is the top, bottom, left, and right sides. Now for more crabs, a good number of crabs found on this hunt had bits and pieces of their underside, legs, and claws here are the nice ones. Crab with imprints of the claws and partial legs. Another crab in similar shape but with a little more of the legs on the underside. Another crab with a portion of the underside of the crab carapace showing. Here is the largest crab found in the past two days, and with a good portion of the underside still preserved and in ok shape! Now here is something I was not expecting at all today, a small sharks tooth, not something I’ve never found but it is now the oldest I have collected. To round everything out I also coveted a small Inoceramid clam half that was in good condition for the sight, as well as some larger Baculites for the strata that I know of, and a set of two Gastropoda and two clams. This will provost be the last hint for the week, we have some rain forecasted for the end of the week and the weekend so here’s to some good erosion.
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Thanks for the info. Time to update yet another data set.
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incredible..., never thought this. We have had some nearly complete jaws of Ptychodus in the german turonian, one was published. But, never thought that it is a lamniform shark. Fantastic find! I will pm you, @ThePhysicist, for the paper lets wait what @Ptychodus04 says, to be a lamniform shark now e.g. I attach the paper (I am not the author) about the german ptychodus jaw GuP_Heft_70_Seite_55-63.pdf
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@ntloux Nice specimens
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Please correct name of Arizona city.
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Definitely horse
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Please correct the spelling of meteorite in the title and tags. Otherwise, searching for meteorite is much less likely to bring up your post.
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BTW I can PM the article if anyone is interested. Ya would be curious to see, but with how complete these are, I doubt a phylogenetic analysis will produce much different results. I'm wanting to understand the algorithms behind these trees - this was done via parsimony, but another method (that may subvert it) is a Bayesian approach which utilizes a similar class of algorithm we use in gravitational-wave astronomy. Interesting thought that might be worth pursuing, I would think convergence is more likely, similar to molariform posteriors in the bonnethead. The diversity of tooth forms within the genus might suggest a diversity of trophic roles? After all we're only seeing the form of one species. A modern analogue might be Carcharhinus which occupy both reefs and the open ocean, so maybe some species of Ptychodus indeed may have specialized on benthic prey.
