Chengjiang puzzle

[Wrangellian]

Here's a specimen I acquired a while back. The worm is quite small (21mm long, ~1mm wide) and hard to photograph but I did my best. The question is, what are those little oval pellet-like things inside (or on) the worm? Its last meal? Parasite? Something taphonomic in nature (I doubt it)? Any ideas would be appreciated!

Not sure of the worm's ID, either. I guess either Maotianshania or Cricocosmia (or Paleoscolex?) They're all so similar I'm not sure how to tell them apart. There should be enough detail - looks like everything including the spiny head/proboscis (left end) is visible.

 

 

 

[RuMert]

No idea, but the specimen and the photo are great - why not post it here:

 

[RJB]

I'm with RuMert, cool fossil but I too have no idea.

 

RB

[Coco]

Eggs ?

 

Coco

[Thomas.Dodson]

My guess is formed fecal pellets before expulsion. @GeschWhat

[Wrangellian]

I thought of that, but would fecal pellets be near the anterior end of the worm?

[GeschWhat]

I took a quick look at worm anatomy.  If those are toward the head they could be contents of the crop and the gizzard (which would be really, really cool). It is also possible that they are worm coprolites deposited incidental to the worm itself. Either way, what a spectacular specimen!

 

[Thomas.Dodson]

21 minutes ago, Wrangellian said:

I thought of that, but would fecal pellets be near the anterior end of the worm?

Generally the gut is rather anterior. The location on your specimen fits.

 

12 minutes ago, GeschWhat said:

I took a quick look at worm anatomy. 

Oligochaetes are pretty far removed from these specimens (Note "Worm" taxonomy is ambiguous in part due to poor fossil records). The species he listed are Palaeoscolecids and Nematomorphs and wouldn't have crops or gizzards. Nevertheless, worms and worm like creatures typically have those long digestive systems that start rather anterior.

 

Since I saw these earlier today I've been curious if these could be sediment pellets like some Polychaetes consume to serve as an anchor for digestive bacteria (Coprinoscolex from Mazon Creek is a famous example). After enough digging to see if there is any evidence Palaeoscolecids do the same I found the following.

 

This is from "New paleoscolecid worms from the early Cambrian north margin of the Yangtze Platform, South China" (Yang Et. al., 2017). Download Link

 

 

 

[Wrangellian]

Thanks both! It looks possibly like we're looking at clumps of sediment in the digestive tract. I'll mark it down as that until I get more info. I'll check out the link soon, thanks Thomas.

[IsaacTheFossilMan]

That's a gorgeous specimen. @Thomas.Dodson had already mentioned what I was going to say, awesome find!

[Wrangellian]

Thanks for all the comments, I guess I was pretty lucky to snag this one a while back! I have more too, I suppose should get some better photos of them than I have already done, but it's tough to get satisfying results. This one is small, but the only one I have with the head end intact.

[RuMert]

10 hours ago, Wrangellian said:

should get some better photos of them than I have already done, but it's tough to get satisfying results

I'm by no means an expert in photographing fossils, but I get OK results with using removable lenses from a jewellers loupe (which I have to use anyway when examining specimens), a smartphone and a few programs (I don't even have a camera, last time I used a camera was 15 years ago). Photoshop works best with stacking photos to remove blurriness with bigger objects (like the worm 100%, in each photo some parts will be clear and some blurry,  Photoshop combines them to make an equally clear picture). I use Faststone image viewer to remove stains and dots, MO picture manager for resizing, cropping, turning, light amelioration and Paint for cropping and combining pictures without much other work). Most often the latter is enough and it's the most basic program ever made.

[Wrangellian]

I don't have a smartphone. I don't have Photoshop either but I have a similar program for photo-editing, plus Paint. I can change brightness, contrast, hue, etc, but none of that does much good if the original pics are not good to begin with. I can take a decent photo in most instances using the macro lens for small stuff and the right settings (when I know what those should be), lighting/angle, tripod, but it's all a hassle. The editing takes time too.

[RuMert]

IMHO with a picture-oriented smartphone (which is not expensive) or a decent camera + sunlight + macro lenses the pictures will be good enough to begin with:) Your worm pic is already very good

[Wrangellian]

I am using a decent camera, but all of the work involved (and trial and error necessary with each specimen I try to photograph, even outdoors) is still a hassle overall. Many days in Winter we don't have any sunlight here, and the days are short, as you know, so I'm restricted to trying to photo them with indoor lighting, which actually would be more convenient if I could get more consistent results.