CLADOENDESIS OF EPHEMEROPTERA

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Pseudiron

(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Branchitergaliae
Heptagennota - Pseudiron)

Nomen hierarchicum: Pseudiron/fg(1) [f:1954; g:1931]

In circumscription fits:

— gen. Pseudiron McDunnough 1931a: 91

— subfam. Pseudironinae Edmunds & Traver 1954a: 127

— fam. Pseudironidae: McCafferty 1991a: 349

— Pseudiron/fg1: Kluge 2000: 251


References. McDunnough 1931a: ; – Needham & Traver & Hsu 1935: ; – Burks 1953: ; – Edmunds & Allen & Peters 1963: ; – Peters & Jones 1973: ; – Edmunds & Jensen & Berner 1976: ; – Pescador 1985: ; – McCafferty & Provonsha 1986: ; – Kluge 2004: .


Autapomorphies of Pseudiron.

(1) Larva with following peculiarities. Mouth apparatus is specialized for carnivorism: mandibles lost their asymmetry, each mandible is shortened perpendicular to axis of articulation, with stout incisor and kinetodontium, prostheca is lost [see Heptagennota (7)], mola lacks grater; superlinguae are lost; maxilla lacks apical-ventral setae, its biting margin is shortened, with 2 canines (instead of three initial ones), proximal dentiseta [see Bidentiseta (1)] is strongly enlarged and looks as a wide dentate sclerotized plate (Kluge 2004: Fig.52:E) (similar modifications of mouthparts occur in some other specialized predators). Labial palp [2-segmented – see Heptagennota (8)] with strongly widened, nearly round 1st segment (unlike Radulapalpata, this segment is flat, and muscles situated in it are not thickened – Kluge 2004: Fig.52:F). Larval body is flattened, pronotum has unique structure (Kluge 2004: Fig.52:A): lateral lobes are expanded far posteriorly, overlapping mesonotum and partly fused with it (that somewhat resembles Ecdyonurus/fg2); mediad of these lobes, posterior margin of pronotum forms a pair of cavities opened backward; margins of cavities bear numerous fine setae; fore protoptera are spread. Larval legs are adopted for inhabitancy on sandy ground: long; tarsus arched; claw are very long, slender, slightly arched, without denticles. Tergalii have unique structure: besides fibrillose lobe [see Branchitergaliae (3)] each tergalius II–VII has a ventral process arising near middle of lamellate lobe.

(2) Patella-tibial suture (initially present on middle and hind legs) is lost on all legs of larva [see (1)], subimago and imago (non-unique apomorphy – see Index of characters [1.2.18]).

Plesiomorphies of Pseudiron. Imaginal and subimaginal furcasternal protuberances are contiguous at anterior part and diverge only at posterior part, inside which metathoracic nerve ganglion is situated [see Heptagennota (4)] (Kluge 2004: Fig.52:B). 1st tarsal segment is fused with tibia (in contrast to Pentamerotarsata) and non-shortened. Penis has no sclerites peculiar for Pentamerotarsata. Maxillary palp is 3-segmented. In contrast to Pentamerotarsata, submentum is well-developed (Kluge 2004: Fig.52:F). In contrast to Pentamerotarsata, larva completely retains primary siphlonuroid swimming specialization: abdomen is large, caudalii with dense long primary swimming setae (only in distal part segments are elongate and lack setation), without secondary swimming setae. Paracercus is subequal to cerci.

Size. Fore wing length 10–12 mm.

Distribution. Nearctic.


Nominal species in Pseudiron/fg(1): 1 species

centralis McDunnough 1931 [Pseudiron] --/

meridionalis Traver (in Needham & Traver & Hsu) 1935 [Pseudiron] — syn.subj. centralis [Pseudiron]

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