(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna pm.Tridentiseta  
Tetramerotarsata Liberevenata Turbanoculata
 Anteropatellata - Baetopus/g1)

Nomen hierarchicum: Baetopus/g1 [g:1960] (incl Raptobaetopus

In circumscription fits:

 gen. Baetopus: Kazlauskas 1962: 41

References. Kazlauskas 1962: '; Keffermuller 1967: ' '; 1984: '; Kluge & Novikova 1992: *; ...?

Autapomorphies of Baetopus/g1.

(1) Labial palp is 2-segmented, 2nd+3rd segment thickened, without muscle inside. In contrast to majority of other Tetramerotarsata, whose boundary between 2nd and 3rd segments and muscle-retractor of 3rd segment are retained.

Characters of Baetopus/g1 of unclear phylogenetic status. 

() Mandibles without setae on inner margin [see Turbanoculata (6)]. Non-unique character, the same in Baetofemorata and some others (see Index of characters [1.1.23]).

() Maxillary palp is 2-segmented. Non-unique apomorphy; the same in selected groups of Cloeon/fg1, et al. (see Index of characters [1.1.42]).

() Tergalii are either unable to rhythmical respiratory movements (see Index of characters [1.3.30]), or make movements of peculiar type (in Raptobaetopus/g1 .

() Imaginal and subimaginal medial longitudinal suture of mesonotum is convex, forming a longitudinal ridge. Probably, plesiomorphy in limits of Liberevenata, as the same in Palaeocloeon, Centroptilum/g1, ...?

() Hind wing [see Turbanoculata (10)] of the "Centroptilum-type": relatively narrow and long, with long hooked costal projection (see Index of characters [2.2.60]).

() ?? penial arms?? (see Index of charcaters [2.3.16a])

Plesiomorphies of Baetopus/g1. 

Lateral sides of larval abdomen without spines, caudalii without dark rings on each 4th joining (unlike Cloeon/fg1). 

In mature larva which is ready to molt to subimago, buds of subimaginal gonostyli are folded under larval cuticle by the "Cloeon-type": 2nd segment of gonostylus is directed laterally, and third segment is curved caudally and medially [see Turbanoculata (13)] (unlike Baetovectata see Index of characters [2.3.9]). 

On fore wing in each space always only 1 marginal intercalary can be present [see Liberevenata (2)] (unlike Baetovectata see Index of characters [2.2.55]).

Size. Fore wing length 35 mm (see Tetramerotarsata).

Distribution. Holarctic and Oriental Regions.

The taxon Baetopus/fg1 is divided into:

1. plesiomorphon Baetopus/g2

2. Raptobaetopus/g1 (incl. Cymbalcloeon)