Posts treating: "Madison County"
Thursday, 19 February 2015
Views of the Mahantango [2015-02-19 09:01:00]
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Devonian; DE,RU,US
I found two little "stumps" of a bryozoan at the Deep Springs Rd. quarry in Madison County, NY. There is not too much to examine as they are fairly small but they resemble the species Atactotoechus fruiticosus. It is interesting to find these specimens as small, individual colonies and not larger, branching versions.This first specimen is a thick, finger like piece with small monticules on the surface. The next few pictures will show different angles of it but this appears to be a single mound [...]
Once a hard shelled animal dies it's shell often lies around on top of the muddy bottom until it gets buried. While it is exposed it provides a hard surface for many other encrusting animals that otherwise would not be able to establish themselves. Today I have two examples of trace fossils that were left on the interior surfaces of pelecypod shells from the Devonian aged Panther Mountain formation in NY.First up is this shell which may be an Actinodesma erectum or another species. It's hard to [...]
Hyoliths are enigmatic creatures that existed from the Cambrian until the Permian. They have triangular shaped shells that are half moon shaped in cross section, an operculum that covered the head and two little horns, called helens, that protruded out from where the operculum and body met. I found a specimen of a Hyolith called Hallotheca aclis in Madison County, NY in the Moscow Formation (Devonian, Givetian stage). The view is of the ventral surface, or underside, of the shell and you can [...]
Here are another group of bivalve fossils that I found at the Deep Springs Rd. Quarry in Madison County, NY. The rock exposed at the quarry is the Moscow formation (Devonian, Givetian stage).The first fossil is a right valve from a Modiomorpha concentra showing the typical elongated oval shape with fine concentric growth lines on the surface of the shell.This species is somewhat common and I've blogged about them being found in the Mahantango Formation Here and Here.The next shell is squished [...]
This smooth, round snail like fossil is actually a cephalopod called a Gonaitite from the Moscow formation (Devonian, Givetian stage) that I found at a quarry off Deep Springs Rd. in Madison County, NY. They were precursors to ammonites and evolved from primitive bactritid type nautiloids. This specimen is a good size but does not preserve the sutures which would help to identify it. Tornoceras sp. is the most common genera in the Moscow formation and this could be a specimen of one. You can't [...]
I found this Camarotoechia sappho brachiopod at the Cole Hill Rd. locality in Madison County, NY. It comes from the Panther Mountain formation (Devonian, Givetian stage). I kept this specimen because it is a nice internal mold of the species whereas many of the other available specimens were just impressions in the rock and clustered tightly together. It's not perfect, however, there is a chip missing off the posterior that took the beak with it. Still it gives me a good representative specimen [...]
Once you get to East-Central NY the Devonian rocks are less limy and more argillaceous and seem to preserve pelecypods better. Thus you get lucky and sometimes find both valves of a pelecypod laid out next to each other such as in this specimen. It's a Pseudoaviculopecten princeps and, while missing a bit of the left valve, is a nice specimen. Pseudoaviculopecten princeps can be identified by the rounded shape of the shell, whose width is greater than it's length, long hinge line with an [...]
This large steinkern, or cast, fossil is a pelecypod that I found at the Cole Hill locality in Madison County, NY. I've been reviewing some resources like "The Paleontology of New York" (James Hall, 1884) and "A field Guide to the Devonian Fossils of New York" (Karl Wilson, 2014) and I think that this fossil is of a Actinodesma erectum. It's a large, oval shaped steinkern with the body vertically aligned (or erect which is where it gets it name) which is unlike many other genera that are [...]
Views of the Mahantango [2015-02-01 09:01:00]
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(746 visits) Devonian; US,ES,NZ
I picked up this slab of chonetid type brachiopods while visiting a small quarry off Geer Rd. in Madison County, NY. The rock found there is a portion of the Upper Ludlowville formation (Devonian, Givetian stage) which has these zones of shell "pavement". Most of the shells I can't really identify beyond "Chonetid type" because to distinguish between the genra you'd need to see if they had spines growing off the hinge line. As the spines are delicate they often get broken off before the shell [...]
I broke this fossil while trying to hand trim some of the excess rock from around it but it glued together pretty well. It's a Paracyclas rugosa from the Panther Mountain formation (Devonian, Givetian) at Cole Hill in Madison County, NY. Paracyclas rugosa is a small pelecypod that is nearly circular in outline and sometimes can be confused with a terebratulid brachiopod.I've posted several examples of this genera before from the Silica Shale, Mahantango Formation, Arkona Formation, [...]
This rock is full of fossils but the one that made me keep it was the impression of a Cornellites fasiculata pelecypod. The detail of the mold is really nice but there is a little "window" in the mold that shows evidence of an encrusting bryozoan that had colonized the shell.This is the whole rock with the impression near the bottom. The rounded object just above it (and casting the shadow) is the pygidium of a Dipleura dekayi trilobite.When you look into the shadowed area you can see the [...]
The pectin like pelecypods of the Devonian can be beautiful with their regular concentric ornamentation highlighted by radial ribs and "wings" along the hinge line. The fossil below is one that I do not recognize but I think I found a name for it while perusing the "Field Guide to the Devonian Fossils of New York" by Karl A. Wilson, 2014, Paleontological Research Institution.On page 148-149 is a pelecypod called Lyriopecten orbiculatus whose description is "Roughly circular shell with [...]
These next two specimens are Cypricardella tenuistriata pelecypod fossils. Both have the typical ovate shaped shell with a squared off posterior margin. The fact that the growth lines are very fine and not terribly distinct or raised eliminates the species C. bellistriata from contention.Both fossils came from a roadside quarry on Cole Hill Rd. in Madison County, NY and come from the Panther Mountain formation (Devonian, Givetian stage) but the rock type is very similar to portions of the [...]
It's rare to find whole Peleycpod shells with no distortion so I was quite pleased to find this Nucula bellistriata fossil. It comes from the upper Ludlowville Formation (Devonian, Givetain stage) at Geer Rd. Quarry in Madison County, NY. Both valves are present and it even appears that one valve may still be preserved with shell material. It would be nice if the hinge line were better exposed but there is a stubborn piece of rock still clinging to that section of the fossil.Right [...]
The outcrop photo below was photographed on 1/21/2013 in Madison County, Arkansas. The shown section is in the uppermost Mississippian limestone. The crinoidal beds display laminations typical of transported sediment. Can anyone say (and justify) if the flow was right-to-left or left-to-right? Put your reply as a
