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Tadpole trace ?


Rockwood

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These are not fossils, but the concept could be useful in understanding ichno fossils.

At first  I came to the pool without tadpoles, it was late in the afternoon on a warm day and I moved slowly as I contemplated how the craters were formed. Had birds been probing the mud ? There did not seem to be a direct correspondence between the tracks and the pits though.

The next pool I came to was deeper and perhaps allowed tadpoles a better escape from predators. The pictures were taken the next morning and the tadpoles were more disturbed by my approach so it doesn't show the behavior, but they seemed to be covering themselves with silt in the pits. Applying sun screen perhaps ? Or is the correlation coincidental ?  

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I believe you are correct, Dale. Tadpole "nests".

See this article

    Tim    -  VETERAN SHALE SPLITTER

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17 minutes ago, Fossildude19 said:

I believe you are correct, Dale. Tadpole "nests".

See this article

These tadpoles live in a spring fed pool in a gravel pit at the foot of a mountain. It rarely dries up and the nests were at the shallow edge. 

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This is really cool, @Rockwood! I'm very interested in this kind of trace fossil at the moment.

"Journey through a universe ablaze with changes" Phil Ochs

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I wonder why they remind me of graphoglyptids, especially Paleodictyon ?

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

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47 minutes ago, abyssunder said:

I wonder why they reminds me of graphoglyptids, especially Paleodictyon ?

The thought had occurred to me. The fact that they are in shallow water seems to support the connection in a weird kind of way.

Frogs have farms ?

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4 minutes ago, supertramp said:

they someway resemble interference ripples

We have had heavy rain lately and such an event could create temporary currents that cross the main flow of the spring.

Any ideas how it could be confirmed or ruled out ?

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Intetesting discovery. That's a really cool observation. I can see that as a published neoichnology article...If it hasn't been noted before. .

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54 minutes ago, Rockwood said:

The thought had occurred to me. The fact that they are in shallow water seems to support the connection in a weird kind of way.

Paleodictyon usually was / is in the abyssal realm, but documents said it was discovered also in shallow water facies, and plus for this, in freshwater environments (see Pickerill, 1990 ).

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

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19 hours ago, Rockwood said:

We have had heavy rain lately and such an event could create temporary currents that cross the main flow of the spring.

Any ideas how it could be confirmed or ruled out ?

I don't believe those are interference ripples, but they do look like that;

in other words: could some fossil interference ripples actually be tadpole traces? 

 

ciao

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3 hours ago, supertramp said:

could some fossil interference ripples actually be tadpole traces? 

I suspect the behavior may be the exception rather than the rule which would lessen the odds, but it may be worth considering.

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Those are fantastic...tadpole traces...very interesting...learned something again. 

 

What kind of scale/approx size are we talking about...they look much larger than the Paleodictyon I ran into years ago...which were smallish in the order of a cm or so...

 

Regards, Chris 

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5 hours ago, Plantguy said:

Those are fantastic...tadpole traces...very interesting...learned something again. 

 

What kind of scale/approx size are we talking about...they look much larger than the Paleodictyon I ran into years ago...which were smallish in the order of a cm or so...

 

Regards, Chris 

If one were to recreate them a golf ball would be the appropriate tool. Something around 3cm in diameter probably. The  legs on the tadpoles were quite well developed.

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can you feel into one of the pits to see if a freshwater clam is in there? Tadpoles living commensally with clams would really be interesting! Have seen aggregations of tads before but they are usually in a mass. The spacing is very regular on the pits.

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Elongated Paleodictyon polygons can reach or may exceed 3cm (P. italicum) in the paleocurrent direction (Kilibarda et al., 2010).

 

Unfortunately  " W. H. Twenhofel. 1939. Principles of sedimentation " is not available, but there's a picture similar to the ones in question.

 

5b57af22aa14f_WhiteandWhite2014Fossiltadpolenests--ararity.thumb.jpg.6e193566edb615fffcab7b7bcc0b1c51.jpg

picture from here

 

Also, in J. D. Gardner. 2016. The fossil record of tadpoles. Fossil Imprint 72 (1-2): 17-44 ,  they are described as:

 

" Putative trace fossils – tadpole nests or holes In fine-grained sediments at the bottom of shallow and low energy water bodies, such as in the backwaters of streams and near the margins of ponds, extant tadpoles sometimes excavate small (up to 55 mm in diameter and 15 mm deep), dish-like depressions that have concave bottoms, are subcircular to polygonal in outline, and are bordered by low, convex- or sharp-topped ridges or berms (e.g., Hitchcock 1858, Kindle 1914, Maher 1962, Boekschoten 1964, Bragg 1965, Dionne 1969, Ford and Breed 1970, Cameron and Estes 1971, Opatrny 1973, Black 1974, Willmann 1976, Metz 1983, Hoff et al. 1999; see also on-line article “Tadpole nests, past and present” at http://blogs.scientificamerican.com/tetrapod-zoology/tadpole-nests-past-and-present/; accessed 24 June 2016). These so-called “tadpole nests”1 or “tadpole holes” (sensu Hitchcock 1858 and Dionne 1969, respectively) are excavated by one or more tadpoles thrashing their tails back and forth immediately above or through loose sediments, presumably while either foraging for food (Kindle 1914, Cameron and Estes 1971, Hoff et al. 1999) or excavating water-filled refuges for themselves as their ponds dry out (Bragg 1965, Ford and Breed 1970). As noted by Black (1974) and Hoff et al. (1999: 221), these structures are notcommonly encountered, but appear to be more prevalent in temporary sites, such as ephemeral pools, ditches, and stretches of shallow water along the margins of ponds.
Tadpole nests occur in aggregations that may cover several square meters or more, with nests either densely packed together in a honeycomb-like arrangement or more broadly separated in a less regular or seemingly random manner (e.g., Kindle 1914: pl. VIII, fig. 2, Maher 1962: fig. 1, Dionne 1969: fig. 1, Cameron and Estes 1971: fig. 1, Willmann 1976: fig. 1). The construction of tadpole nests appears to be widespread among modern anurans: tadpoles belonging to at least three families (bufonids, hylids, and scaphiopodids) have been observed excavating or in direct association with tadpole nests in both Europe and North America (e.g., Bragg 1965, Ford and Breed 1970, Black 1971, 1974, Cameron and Estes 1971 and references therein, Opatrny 1973, Willmann 1976, Hoff et al. 1999). " (...)

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

My Library

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15 hours ago, Plax said:

can you feel into one of the pits to see if a freshwater clam is in there? Tadpoles living commensally with clams would really be interesting! Have seen aggregations of tads before but they are usually in a mass. The spacing is very regular on the pits.

I will try, but it seems doubtful. This is still an active pit that is some distance from other bodies of water. I doubt this level has been exposed long enough to establish a population even if it had been seeded somehow.

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I think that Abyssunder's Scientific American article proves they are tadpole nests. And to think that I fancy myself an amateur herpetologist!

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One week later after more heavy rains. 

The algae would perhaps be instrumental in preserving these features. If they were in an overall depositional environment. These will never make it.

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38 minutes ago, Rockwood said:

One week later after more heavy rains. 

The algae would perhaps be instrumental in preserving these features. If they were in an overall depositional environment. These will never make it.

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Very interesting! Is neoichnology really a field? When taking a photo like the two above, a polarized filter helps eliminate the reflection of the sky. If using your cell phone, just snap the photo through your sunglasses 

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22 minutes ago, Scylla said:

Is neoichnology really a field?

Most definitely. A basic understanding of such concepts is key to understanding the fossil record. 

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13 hours ago, Rockwood said:

These will never make it.

To have these preserved would take a particular set of circumstances. I think there would have to be many years of drought following the original forming of the traces for them to become trace fossils. I imagine the sun would contribute to hardening/baking of the depressions, as with clay. Then some years later when rains began again, the hardened depressions would fill with silt and debris and the formation of more layers, etc. Fun to think about.

"Journey through a universe ablaze with changes" Phil Ochs

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7 hours ago, Innocentx said:

To have these preserved would take a particular set of circumstances. I think there would have to be many years of drought following the original forming of the traces for them to become trace fossils. I imagine the sun would contribute to hardening/baking of the depressions, as with clay. Then some years later when rains began again, the hardened depressions would fill with silt and debris and the formation of more layers, etc. Fun to think about.

Many times all it takes is a layer of material that acts as a divider between the bedding layers.

These sediments will almost certainly eventually make their way to the Atlantic before they get their chance though. The area has been an erosional environment since the Appalachains got their start during the Devonian. 

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