Tylenchorhynchus robustus
Thorne & Malek, 1968
Photo Gallery- Konza Prairie

L = 1.0 mm; V = 52
Body arcuate when relaxed, tapering anteriorly to a bluntly conoid lip region without visible annules. Lateral fields marked by 4 incisures, the outer ones crenate.  Spear 23u long with moderately large, slightly cupped knobs, their muscles attached to sclerotized band about base of head.  Dorsal esophageal gland outlet about 2u behind spear knobs. Esophagus tapering to a narrow tube where it joins the median bulb.  Basal bulb about as long as neck width with excretory pore opposite anterior end.  Hemizonid 1 annule anterior to pore.  Deirids not seen.  Ovaries outstretched, oocytes in single file.  Spematheca about half as long as body width, packed with sperms.  Eggs almost 3 times as long as body width.  Intestine extending entire length of tail cavity, the rectum attached to ventral side.  Tail with 40-45 annules and massive thick cuticle around hemispheroid terminus. Male with lateral field, bursa, spicula, gubernaculum and phasmid as illustrated.

Tylenchorhynchus robustus is immediately recognized by the long cylindroid female tail with smooth rounded terminus, and bluntly rounded lip region without visible annules.
Habitat:  Four females and 6 males from soil about roots of native pasture grasses, Range Field Station, Cottonwood, South Dakota.
(Description- Thorne & Malek, 1968)

DNA Sequences Obtained
Specimen: Collected:
KonzaVIII EE-78 Konza Prairie, First survey
KonzaVIII EE-46 Konza Prairie, First survey