Search the Community

I just came back from a surveying trip with some specialists from the museum this weekend, and naturally on the day after they left I happened to come across this oddball... It's really nothing like I've ever seen in the area before. The fossil itself is a piece of fragile lignitic wood inside a sandstone concretion, found in a thin layer of the late cretaceous marine Bearpaw formation associated with trace burrow fossils, and known to be deposited in a near-shore deltaic environment. Very well preserved, fragile lignitic wood is common, as well as other trace burrow fossils (you can see some in the concretion itself), which leads me to believe that these are infilled burrows of some kind (termites?). But I've never seen burrows in fossil wood that look like this, never mind in mud or any other substrate. They look to be too closely clustered together to be burrows, as in most substrates this would cause the walls between them to collapse. I know the chances are astronomically low, and that this almost definitely isn't the case, but this looks the most to me like some sort of fungal colony more than anything. Could it be a trace fossil of some kind of fungus or plant? I only have these photos from the field currently, as the specimen is currently jacketed, but I might have a chance to get some better photos either tomorrow or sometime later this week. (PS, I still find myself unable to upload any images to the forum. I get an error message that says, "The page you are trying to access is not available to guests, but may be available if you sign in.") View of concretion Note the lignitic wood still clinging to the top and bottom of the hollow once presumably filled by it. Left close-up Right close-up Some of the smaller "nodules"

I frequently come across golfball-sized concretions in the marine sandstones of the Late Campanian Bearpaw formation exposed at Lake Diefenbaker, Saskatchewan. Nearly all have small coalified fossils inside, ranging from fish bones to decapod fragments, wood chips, and all other manner of organic detritus. These remains are often difficult to identify (certainly beyond my ability, anyway), typically because they are either too crushed to be recognizable, or have been split on a bad plane. The following photos shows one of these nodules collected last weekend, that caught my eye with its regularity. As you can see, there is a small row of mostly uniform nodules inside, with thin sandstone rinds discontinuous to the matrix, and filled with a black, coal-like mineral, the same which tends to replace other organic remains found in similar nodules. Any ideas? For reference, here are some other fossils found in similar nodules from a similar layer of the formation, including fish vertebrae and a decapod claw:

I thought the mosasaur fans here might enjoy a fairly recent bit of mosa-research… This paper describes the very well preserved skull and associated postcrania (a few vertebrae, some pectoral and pelvic girdle elements, a partial forelimb and a hindlimb) of a new tylosaurine mosasaur species, Tylosaurus saskatchewanensis. The holotype material of this tylosaur is from the Upper Campanian (Late Cretaceous) Bearpaw Formation of Saskatchewan, Canada. The paper: Jiménez-Huidobro et al. 2018 new Tylosaurus species.pdf A sneak peak at some of the material described (articulated dorsal vertebrae) - scale bar is 10cm: Hope you guys like it