PalaeognoristeMeunier 1904 : 87; Meunier 1912 : 89; Matile 1990a : 360; Matile 1990b : 366, 373-376, 383, 409, 421, 554; Hoffeins and Hoffeins 1996 : 311; Grimaldi and Blagoderov 2001 : 55; Hippa et al. 2005 : 5, 11; Blagoderov et al. 2009 : 32, 33, 35, 37, 45.
Type species.
Palaeognoriste sciariformeMeunier 1904 : 88, by monotypy.
Diagnostic description.
Small lygistorrhinid flies. Proboscis medium length, about the length of fore tibia, palpus one-segmented, shorter than labellum. Three ocelli, median ocellus smaller than lateral ocelli. Scutum evenly setose with medium-length setae, laterotergite bare. Wing venation similar to Parisognoriste but Rs transverse (illustrated in Grimaldi and Blagoderov 2001 : fig. 5a): Sc joining C. R1 short, approximately half of wing length. Rs distinct. R5 setose. Base of fork M1 and M2 incomplete, but traceable. M3+4 and CuA without a common stem. Crossvein m-cu well developed and aligned with crossvein r-m. R1 setose, Sc, R5, M, and CuA bare. Hind leg much longer that both fore and mid leg, hind tibia enlarged apically. Tibial vestiture in rows. Basitarsomere 3 inflated. Male tergite 9 with aggregation of thickened setae at apex.
Discussion.
Palaeognoriste is distinguished from all other described fossil taxa of Lygistorrhinidae by the structure of mouthparts and from all recent genera by, for example, a well-developed Rs and r-m (see below under Phylogenetic analysis).
