Paraxonchium magnidens
Thorne, 1974
Photo Gallery- Nine-mile Prairie
Photo Gallery- North Dakota Potato

1.5 mm; a = 26; b = 3.6; c = 30-37; V = 60
Body tapering rapidly until lip region is only 1/5 of neck base.  Lateral fields about 1/6 body width with obscure cells from which series of obscure pores arise, while ventrally another more prominent series come from gland-like bodies, about 40 anterior to vulva and 25 posterior.  Lip region set off by deep constriction with angular unsymmetrical lips which are best observed from a face view.  Amphids shallow, cup-like, about half as wide as lip region.  Spear 15u long with aperture occupying 1/3 to 2/5 its length.  Spear often somewhat bent, asymmetrical.   Hemizonid conspicuous, opposite nerve ring.  Esophagus enlarged near middle with gland nuclei usually visible.  Three nygolaimoid glands at base of eophagus.  Cardia an elongate disc, then conoid.  Intestine usually gorged with detritus whichi appears to have been deribed from decaying organic material.  Ovaries symmetrical, reflexed about half their length.  Eggs 46x90u.  Vulva transverse with sclerotized labia.  Prerectum length 2-3 times body width. Rectum and tail as illustrated.  Males not collected and gravid females contained no sperms.  Paraxonchium magnidens is distinctive because of its size, monosexuality, dorylaimoid spear and asymmetrical lips.

Habitat:  Small numbers from virgin and cultivated soil in numerous localities of South Dakota, State line between North Dakota and Montana on Highway 94, Fonda and Minot, North Dakota and Elizabeth, Minnesota.  Specimens from Minot, North Dakota and Hammer, South Dakota had slightly shorter necks: b = 4.0: 4.3/
     The taxonomic postion of Paraxonchium is questionable.  Jairajpuri (1966) assigned it to Dorylaiminae but it may represent an entirely new group.
(Description- Thorne, 1974)

DNA Sequences Obtained
Specimen: Collected:
Watson SE-1
Salting 2
ND19-01 North Dakota Potato survey