devonian sponge or not

[val horn]

this was found in deer lake pa on a large piece of shale.  whatever these things are they are over 12 inches long, branching and 1/2 to 3/4 inch in diameter. occasionally they appear to have straight vertical lines on the surface.  I could see this pattern in only one or two places and could not get a clear photo.  Help would be appreciated.

[LabRatKing]

I would classify these as Thalassinoides a type of ichnofossil believed to be burrows of critters related to mantis shrimp. (though there are other invertebrates that make these types of trace fossils too still called Thalassinoides)

[Jeffrey P]

4 minutes ago, Jeffrey P said:

A more closeup detailed photo would be helpful. Do your specimens look like this? I found this at Deer Lake a few years ago. Never could ID it, but suspect it is a sponge or bryozoan. 

[val horn]

hi jeffrey.  My fossil does not have anywhere as clear a surface structure as yours shows.  a couple of areas seemed to have thin vertically oriented lines (could not get a good clear photo).  They may well be the same thing, thought i dont have much surface texture while mine appear more rounded in contour.  LabRatKing suggested Thalassinoides .  It is kind of disappointing (having carted out this hung piece of shale)  it looks right.

[LabRatKing]

15 hours ago, 10313horn said:

hi jeffrey.  My fossil does not have anywhere as clear a surface structure as yours shows.  a couple of areas seemed to have thin vertically oriented lines (could not get a good clear photo).  They may well be the same thing, thought i dont have much surface texture while mine appear more rounded in contour.  LabRatKing suggested Thalassinoides .  It is kind of disappointing (having carted out this hung piece of shale)  it looks right.

Don't be disappointed! Thalassinoides  is an excellent indicator that other fossils are present in the rock, you just have to do some chipping and breaking to find out.

 

For instance, in the formation near me, finding the Thalass means you reached the "bottom" of that member...and ours are interlaced through everything from crinoids and brachiopods to shark teeth and trilobites.

 

I haven!t been to Deer Lake in decades (I'm a spawn of Erie...), but there are lots of great fossils to find there...and I bet there are more than a few in the chunk you brought home so get crackin' so to speak!

 

Is the Township quarry backfill dump still there? We used to fill BUCKETS with great fossils from that site.

[LabRatKing]

19 hours ago, Jeffrey P said:

A more closeup detailed photo would be helpful. Do your specimens look like this? I found this at Deer Lake a few years ago. Never could ID it, but suspect it is a sponge or bryozoan. 

Yep, bryozoan.