Hi, José

it looks like a Thalassionoides,that is usually marine, and can be associated to omission surfaces, indicating some sediment erosion/removal before bioturbation? Is this related to a possible transgressive surface (and lag deposit...) over the continental deposits? You should contact professor Renata Guimarães Netto, from Unisinos university, which you can find here in research gate. Good luck, best regards. Buena suerte!

Thanks for your useful response Roberto

I am not a trace fossil expert, but Thalassinoides usually has a horizontal Y-branching pattern, while this specimen is clearly some kind of vertical burrow system. Sorry I can't give more help than that.  Nice photo, though!

Peter

Gasca, you can try too with Jose Carlos García Ramos. He published some papers about other icnofossils, not only dinosaurs footprints in which he became specialised. Although this studies are a bit older in age, maybe he can tell you something.

Here I send you the tipe of studies he did:

García-Ramos, J. C. 1978. Estudio e interpretación de las principales facies sedimentarias comprendidas en las formaciones Naranco y Huergas (Devónico Medio) en la Cordillera Cantábrica. Trabajos de geología, 10(10), 195-249.

http://geol00.geol.uniovi.es/TDG/Volumen10/TG10-09.PDF

García-Ramos, J. C., Suárez de Centi,  C.,  Valenzuela, M. 1992. Icnofósiles, sedimentación episódica, tempestitas fangosas y «black shales» de ambientes seudoanóxicos, en sucesiones marinas de plataforma y rampa." Geogaceta, 12, 99-100.

Suárez de Centi, C., García-Ramos, J. C., Valenzuela, M. 1989. Icnofósiles del Silúrico de la zona Cantábrica (NO de España)." Boletín geológico y minero, 100, 35-90.

And, although maybe he cant help you, they organised few years ago the XI International Ichnofabric Workshop and in the information of this Congress maybe you can find who is working with this kind of bioturbation.

Anyway, about Thalassinoides, it does not seem to me according to the Thalassinoides I have seen, but is a photo. So I leave you here two links with information about this:

http://paleoviva.fc.ul.pt/Huelvagps/Inovadoc01/Guiabarran01.pdf

http://cretaceous.ru/files/pub/temp/yanin_ea_2013_nory_thalassinoides_draft_en.pdf

Good luck!!!

Thanks to all for your advices!

if continental it seems a beetle or insect vertical burrow to larval development, see Hasiotis and their works

If this one is from coastal plain than there is a certain possibility taht  it can be some kind of Thalassinoides. I have seen similar trace fossils in Müchehagen, assoiciated with a dinosaur tracksite.

There can be some vertical element and in large burrows even anastomosing structures (with the typical Y-branching pattern or more seldom with a T-branching pattern).

By the way: I think I can see these typical Y-branching of the burrow in the uppermost part of teh photograph. There is also a different branch, with a slightly more horizontal dip I think, on the left part of the photograph.

All in all, I feel pretty confident calling this Thalassinoides.

From the photograph it appears to be Thalassinoides. The branching pattern however is not clear. Thalassinoides and similar traces are attributed to various crustaceans and hence can occur different environmental settings. There are several publications dealing with this aspect

Thalassinoides are usually "Y"-shaped. Difficult to identify from the photograph.

Dear Jose

Thalassinoides seemas Y shape whereas the figures is so difficult to identify this form. but it looks like  to Planolites. according to Alpert (1975), it had been recorded in shallow water sediments (attached file). Similar data was recorded from south India byMalarkodi et al. (2009).

link: http://link.springer.com/article/10.1007%2Fs12594-009-0190-x 

Regards

Massih

Planolites are usually along the bedding, this one seems to be across the bedding--a burrow.

Dear Jose

Thalassinoides as I know is not only  a horizontal trace (T. suevicus). There is also a vertical type, named as Thalassinoides paradoxicus. Therefore, the vertical-oblique bioturbation in your photo is possible to be Thalassinoides paradoxicus if you can find Y-branch patterns somewhere nearby.

Best luck!

Eason Hong

The Vertically oriented, "Y" shaped trace fossils are usually attributted to Ichnogenus Psilonichnus. This seems more like Psilonichnus rather than Thalassinoides. 

The Vertically oriented, "Y" shaped trace fossils are usually attributted to Ichnogenus Psilonichnus. This seems more like Psilonichnus rather than Thalassinoides. 

I agree absolutely that it is Thalassinoides, a trace made by crabs. I have mapped them in the Cretaceous deposits but are not time restricted.

Obianuju P. Umeji

Thalassinoides burrow is more likely.

Hola, pudiste resolver que icnotaxón puede ser? Yo lo veo dudoso también pero tiene similitudes con Eggbelichnus (Hyzny et al., 2015).

From the posted images, dated April 10, 2021, the burrows appear to be from a pedogenized mudrock horizon and might be Camborygma isp. supposedly produced by land-dwelling crustacean Crayfish.

For further confirmation, you might talk to Dr. Mariano Germán Arregui at La Plata and also to Dr. Mariano Verde, Universidad de la República de Uruguay. Please feel free to write me as well.