(Kieffer, 1912)
Body
Small larvae up to 4 mm long. Freshly preserved larvae are violet. The thorax has only two segments. Numerous stout setae on the body, longer than the segment. The anterior and posterior parapods are separate and bear rows of claws. Procercus and two pairs of anal tubules present (Wiederholm, 1983; Moller Pillot, 1984b).
Head
The head length is 0.198 - 0.270 mm (Moller Pillot, 1984b; Schmid, 1993).
Antenna
The antennal length is 50 -75% of the head length and consists of five yellow segments. The antennal blade is short and the lauterborn organs are small.
Mentum
The mentum has two median teeth and 5 pairs of lateral teeth Thienem partita ment pict. The ventromental plates are weak. The beard is absent.
Labrum
The pecten epipharyngis consists of three triangular spines, SI is weak and the premandible has one apical tooth (Wiederholm, 1983; Moller Pillot, 1984b).
Mandible
The mandible has an apical tooth and 4 inner teeth. The seta interna has plumose branches (Wiederholm, 1983).
Differential characteristics
The antenna of Thienemanniella is distinctive, shorter than the antenna of Corynoneura and not on a pedestal like Heterotanytarsus Antenna half headlength.
T. acuticornis can be separated from the other Thienemanniella by the violet bodycolour and/or the long setae on the body segments.