Hyolith helen?

[Nautiloid]

Hello all!

 

I’ve done a ton of collecting in the Hamilton Group of the finger lakes the past couple years. While my main focus is the trilobites, I occasionally find some neat associated fauna worth keeping. I collected this plate back in September which features 2 different species of hyoliths right alongside one another. The larger of the two has an associated operculum, which is quite uncommon from what I’ve gathered. I was just looking over the piece again and noticed a slender, tapered shape which appears to be connected to the operculum, and my first thought was maybe a helen. Just wanted to post it on here to get some other opinions, as I’ve never heard of Hamilton Group hyoliths being found with their helens before. 

Thanks!

 

First pic shows the whole plate, second pic is zoomed in on the operculum with possible helen. 

[Fossildude19]

Some context may be required:

 

"2.3. Helens and their function

The presence of helens is another character that distinguishes hyolithids from orthothecids. Helens, first described by Salter (1866), are relatively long, narrow, and curved skeletal elements, which form paired appendages or spines lateral to the hyolithid conch (Yochelson, 1961, Yochelson, 1974; Marek, 1963; Runnegar et al., 1975; Marek et al., 1997b; Babcock and Robison, 1988). There is no evidence to suggest that any external soft parts were associated with the helens (Babcock and Robison, 1988; Martí Mus and Bergström, 2005). Helens have an anteroposteriorly flattened elliptical cross section and they are usually ornamented by a series of closely spaced growth lines (Marek, 1963; Yochelson, 1974; Martí Mus and Bergström, 2005, Martí Mus and Bergström, 2007; Martí Mus et al., 2014). The orientation of the helens (directed backwards or upwards in relation to the conch) was long controversial due to the paucity of direct evidence (Martí Mus and Bergström, 2005). However, it is now generally accepted that the helens must originally have curved downwards and were inserted in the lateral slit, sloping posteriorly between the conch and operculum (Runnegar, 1980; Martí Mus and Bergström, 2005, Martí Mus and Bergström, 2007; Malinky and Yochelson, 2007; Martí Mus et al., 2014)."

 

SOURCE

 

 

 

 

 

 

Cropped, rotated, and darkened a bit:

 

[Jeffrey P]

Wow! That is an incredible find. Big congratulations and thanks for sharing it. You know I'll be reexamining all of my hyolithts see if anything like that is present. 

[Bringing Fossils to Life]

I'm skeptical, as other preserved helens I've seen pictures of have ridges running across the structure instead of down it. I think that the structure in question is a shell that has been weathered with the rock to reveal a cross section at an angle. You found a great specimen; I've never seen a Hallotheca with an articulated operculum before, only having read about them.