This is Mazon Monday post #198. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Figure 11.1, Priapulida konecniorum; modified after Shabica and Hay (1997). Scale bar = 5 mm.
Priapulites konecniorum is an extinct species of priapulid worm. Priapulida is a phylum of unsegmented marine worms. The name relates to the Greek god of fertility. Due to their shape and their extensible proboscis, they are sometimes referred to as "penis worms". P. konecniorum is a rare fossil find; specimens are mostly known from Pit 11.
P. konecniorum was described in 1973 by Frederick Schram in "Pseudocoelomates and a nemertine from the Illinois Pennsylvanian", which was published in the Journal of Paleontology.
Abstract
Four species of soft bodied worms are described from the Mazon Creek area, Middle Pennsylvanian, of Illinois. They are assigned to four phyla, three at the pseudocoelomate grade of organization: Priapulida (Priapulites konecniorum), Nematoda (Nemavermes mackeei), and Chaetognatha (Paucijaculum samamithion); and to the phylum Nemertea (Archisymplectes rhothon). These Mazon Creek worms are very similar to their living relatives. The fossils display the ancient origins of these phyla which are now seen to have existed virtually unchanged since at least the Middle Pennsylvanian.
The animal is named for Jim and Sylvia Konecny, who are well known to ESCONI members. In the photo below, Jim Konecny is on the left, while Sylvia is in the middle. They are presenting a dedication to Lucy McLuckie for her husband John, after his death in 1963. Both Jim and Sylvia were very active in ESCONI for many years. They were prolific collectors. The majority of their collection was donated to the Field Museum in 2019.
Name derivation.-Named in honor of Mr. and Mrs. James Konecny, Mokena, Illinois, who brought in the first specimen to the Field Museum and donated the holotype.
In the credits, Schram lists various collectors with specimens - Dan Damrow, Jerry Herdina, Ted and Helen Piecko, Francis Tully, and William Popp. All of them ESCONI members!
In the course of this study, specimens from several collections, most of them private, have been used. Prefixes denote these in the text as follows:
- PE, Field Museum of Natural History, Chicago.
- EX, private collection of Mr. Daniel F. Damrow, Norridge Park, Illinois.
- H, private collection of Mr. Jerry Herdina, Berwyn, Illinois.
- HTP, private collection of Mr. and Mrs.
- Ted Piecko, Chicago, Illinois.
- T, private collection of Mr. Francis Tully, Joliet, Illinois.
- Private collection of Mr. William Popp, Chicago, Illinois.
P. konecniorum can be found on page 11 of "The Mazon Creek Fossil Fauna" by Jack Wittry.
Priapulites konecniorum Schram, 1973
Priapulites konecniorum is a worm-like animal which likely lived in soft sediments and preyed on other invertebrates. Sustenance may have consisted of soft-bodied animals such as polychaete worms, characteristic of its modern relatives' diet. Priapulites would catch their quarry by extending a spined pharynx out of its mouth, grasping the prey while rapidly retracting the pharynx back into the gut.
Typically, the field marks are a bulbous proboscis that has lateral lines running down its length, often with a well-marked mouth opening. The trunk of the body is ringed, but not truly segmented as with members of annelid worms.
The "Richardson's Guide to the Fossil Fauna of Mazon Creek" mentions P. konecniorum in chapter 7B "Nonannelid Worms", which was written by Kirk Fitzhugh and Steven D. Sroka.
Priapulites konecniorum Schram, 1973 Figures 7B.2, 7B.4C
Description. Body 4-6 cm long, composed of introvert, trunk, and caudal appendage (Figures 7B.2, 7B.4C). Introvert slightly inflated, with 16 to 20 papillate, longitudinal ridges; little detail visible in anterior most region. Trunk of even width; cuticle with 30 to 40 distinct annulations. Caudal appendage poorly preserved, appearing paired in some specimens.
Remarks. The species is rarely found. Priapulites konecniorum closely resembles the extant species, Priapulus caudatus Lamarck.
P. konecniorum appears in the "ESCONI Keys to Identify Pennsylvanian Fossil Animals of the Mazon Creek Area", along with some nice artwork by Don Auler.
Priapulites konecniorum
This worm has a trunk clearly marked with 30 or more annular rings; number of rings may vary with size. Proboscis had 12 or more, lengthwise warty ridges. Surface markings give this animal the most ornately decorated body of the Essex worms. The average length is 55 mm with tail end seldom preserved, although two fan-like appendages are faintly visible on some specimens. Recent priapulids bear spines around their mouth apparatus, so it is assumed that P. konecniorum similarly equipped.
Specimens
