From whom are those ichnofossils ?

[fifbrindacier]

Hi, i found those traces in the South of France, on the border of the river Dourbie, i guess this is geddinian.

@Johannes told me it was a combination between Dimorphichnus and Cruziana.

[Tidgy's Dad]

Looks closer to Dimporphichnus to me. 

Cruziana wouldn't be stacked like that and not continue further horizontally. 

[Johannes]

Only the second shown specimen is going into Cruziana-direction (or maybe Rusophycos, more likely), you can cleary see the oposite scratch marks turning into digging marks. Nice to see: the burrowing can be seen for each leg seperatly, making this sample so beautifull!

 

The first one I would assing to Dimorphichnus.

[fifbrindacier]

[fifbrindacier]

Those ones are from a Flysch of the cretaceaous : Trichichmus linearis ?

[fifbrindacier]

[fifbrindacier]

For that one, i have no clue.

[SailingAlongToo]

54 minutes ago, fifbrindacier said:

For that one, i have no clue.

I really like this one!

[Johannes]

The last one is interesting, too. I would say some Cruziana in different states of undertraces..

[fifbrindacier]

Here is a detail of it :

[Johannes]

Difficult to see some details in the marked area... But the small "sausages" in the upper right and lower left look like Treptichnus cf. pedum at some areas...

[fifbrindacier]

I particularly love that one :

[Johannes]

26 minutes ago, fifbrindacier said:

I particularly love that one :

The middle one can be a Diplocraterion isp. (but also some others are possible), the ones in the lower left and right  are harder to identify (but not less interesting)

[fifbrindacier]

Thanks Johannes, i particularly love that one. They're all traces of life in movement, but i find this one particularly shows that.

[ynot]

2 hours ago, fifbrindacier said:

They're all traces of life in movement,

Nice trace fossils !

[abyssunder]

Could we know the geological age of each specimen?

[fifbrindacier]

The first three are Gedinian (lower Devonian) they are micaced (i believe Sandstone) and the others are Maestritchian, limestone.

[abyssunder]

I would compare the parallel to subparallel ridges/grooves of the first two specimens with Monomorphichnus.

 

 

 

excerpt from M. Sharma et al. 2018. Observations on the ichnospecies Monomorphichnus multilineatus from the Nagaur Sandstone (Cambrian Series 2-Stage 4), Marwar Supergroup, India. J. Earth Syst. Sci. 127:75

[abyssunder]

This specimen has very nice bivalve traces, comparable to Protovirgularia, in my opinion.

 

 

excerpt from M. Nara and Y. Ikari. 2011. “Deep-sea bivalvian highways”: An ethological interpretation of branched Protovirgularia of the Palaeogene Muroto-Hanto Group, southwestern Japan. Palaeogeography, Palaeoclimatology, Palaeoecology 305: 250-255

 

excerpt from J. M. de Gibert & R. Domènech. 2008. Trazas fósiles de nuculoideos (Protovirgularia) del Mioceno marino de la Cuenca del Vallès-Penedès. [Nuculoidean trace fossils (Protovirgularia) from the marine Miocene of the Vallès- Penedès Basin.] Revista Española de Paleontología, 23 (2): 129-138

 

[abyssunder]

20 hours ago, fifbrindacier said:

The first three are Gedinian (lower Devonian) they are micaced (i believe Sandstone) and the others are Maestritchian, limestone.

Thank you!

[piranha]

On 1/5/2019 at 10:50 AM, fifbrindacier said:

For that one, i have no clue.

 

 

Scolicia plana

 

 

figure from:

 

Uchman, A. 2004

Deep-sea trace fossils controlled by palaeo-oxygenation and deposition: an example from the Lower Cretaceous dark flysch deposits of the Silesian Unit, Carpathians, Poland.

Fossils and Strata, 51:39-57  PDF LINK

[abyssunder]

If we take as reference Đaković et al., 2018, we can have a totally different aspect of Scolicia plana, to be more precise, there may be two preservation forms, one presented in Uchman, 2004 - epichnial, the second presented in Đaković et al., 2018 - hypichnial.

 

excerpt from M. Đaković et al. 2018. Ichnofossils from Cretaceous-Paleogene flysch of Mide locality (Budva Zone, southern Montenegro). Geoloski anali Balkanskog poluostrva 79: 11-18

 

" Martinsson ’s clasification
The classification system proposed by Martinsson (1970) has a lot in common with that of Seilacher (1964b), including the fact that it is also based on the relationship of the trace fossil to a casting medium. Four preservational categories were introduced: epichnia, hypichnia, endichnia, and exichnia. Epichnial preservation comprises structures preserved at the upper surface of the casting strata, while hypichnial preservation includes those preserved at the lower surface of the casting strata. In both epichnial and hypichnial preservations, the terms grooves and ridges are used to denote negative and positive reliefs, respectively.
Endichnial preservation refers to structures preserved within the casting medium and exichnial preservation comprises those preserved outside the casting medium. " - according to Buatois and Mángano, 2011

 

Considering all the above, I'm not convinced that the traces are Scolicia plana, but I'm more convinced that they may be Protovirgularia. I could be wrong,also.

[piranha]

The diagnosis for Protovirgularia is straight to slightly curved.  The posted specimen has horseshoe-shaped turns.

[abyssunder]

Is there anywhere specified that Scolicia has that distinguishing character?
Bivalves may have extreme turns in their trackways.

 

[piranha]

1 hour ago, abyssunder said:

Is there anywhere specified that Scolicia has that distinguishing character?

 

 

Uchman 2004 clearly illustrates this feature in figure A, posted above.  Uchman & Krenmayr 1995 has a more detailed description:

 

Scolicia DE QUATREFAGES 1849

Diagnosis : Variably and commonly selectively preserved, simple, winding, meandering to "coiling" bilobate or trilobate back-filled burrows with two parallel, locally discontinuous, sediment strings along their lower side. Cross-section approximately oval in outline.  Lower side between the strings flat or slightly concave. Backfill laminae composite, may be biserial on the upper side.  Washed-out forms preserved as hypichnial bilobate ridges (after UCHMAN 1995).

 

Uchman, A. & Krenmayr, H.G. 1995

Trace fossils from lower Miocene (Ottnangian) molasse deposits of Upper Austria.

Paläontologische Zeitschrift, 69(3-4):503-524