Compare

Rossithidium pusillum has smaller valves, lower stria density, and more narrow axial area on the raphe valve.

Rossithidium petersenii has much larger central area on the raphe valve and a wider, rhomboid axial area on the rapheless valve.

Achnanthidium crassum has valves that are slightly arched. Striae on the raphe valve are radiate with greater stria density at the ends.

LM scalebar = 10 µm
Rossithidium anastasiae LM2 Rossithidium anastasiae LM6 Rossithidium anastasiae LM3 Rossithidium anastasiae LM4 Rossithidium anastasiae LM7 Rossithidium anastasiae LM8 Rossithidium anastasiae LM1
Length Range
12-26 µm
Width Range
3.7-4.5 µm
Striae in 10 µm
24-29

Rossithidium petersenii

(Hust.) Aboal in Aboal, Alvarez-Cobelas, Cambra and Ector 2003

Rossithidium petersenii LM7 Rossithidium petersenii LM4 Rossithidium petersenii LM6 Rossithidium petersenii LM1 Rossithidium petersenii LM3 Rossithidium petersenii LM2 Rossithidium petersenii LM5
Length Range
13-18.5 µm
Width Range
3.5-4.5 µm
Striae in 10 µm
32-36

Rossithidium pusillum

(Grunow) Round and Bukht. 1996

Rossithidium pusillum LM6 Rossithidium pusillum LM8 Rossithidium pusillum LM10 Rossithidium pusillum LM2 Rossithidium pusillum LM4 Rossithidium pusillum LM12
Length Range
10–16 µm
Width Range
3.1-4.1 µm
Striae in 10 µm
20-24

Achnanthidium crassum

(Hust.) Potapova and Ponader 2004

Achnanthidium crassum LM5 Achnanthidium crassum LM4 Achnanthidium crassum LM1 Achnanthidium crassum LM2 Achnanthidium crassum LM3 Achnanthidium crassum LM6
Length Range
7.3-19.6 µm
Width Range
3.1-4.5 µm
Striae in 10 µm
17-24