Abstract
Three new fossil species from Burmese amber are described, one clearly in family Calamoceratidae, the other two in the highly variable family Odontoceridae. The family Odontoceridae contains 18 disparate genera, but there are no good diagnostic characters, which makes it difficult to place fossil taxa in this family. We here offer a revised diagnosis for the family, highlighting the lack of good diagnostic characters, and the need to use sets of characters to place (extinct) taxa in this family. On this taxonomic basis we describe two new species in the hitherto monotypic fossil genus Palaeopsilotreta Wichard & Wang, 2017 (Odontoceridae), Palaeopsilotreta burmanica sp. nov. and P. cretacea sp. nov., redescribe the type species based on additional information, and describe features of the female, based on two specimens, one of which is embedded adjacent to a male identified as P. xiai. Males of Palaeopsilotreta bear bipectinate antennae; the antennae of the females are simple and filiform. Similarly, bipectinate antennae are present in the third species we describe, Bipectinata orientalis gen. et sp. nov., which otherwise lacks the character combinations associated with the Odontoceridae, but clearly can be assigned to the family Calamoceratidae.
Highlights
Trichoptera Kirby, 1815 in Burmese amber have been shown to include several morphological features not present in extant species (Wichard & Wang 2017; Wichard et al 2018)
Diagnosis Palaeopsilotreta can be placed in the family Odontoceridae based on the following combination of characters: ocelli absent; spur formula 2/4/4; males with five segmented maxillary palps, first segment without apicomesal nodule, terminal segment not flexible or annulated; mesoscutum with a pair of ovoid setal warts, mesoscutellum covered by a single wart, large, dome-like and ovoid; presence of forewing forks I, II and V in both wings; discoidal cells closed, median and thyridial cells absent
The long geological time span corresponds to a sequence of around 100 million generations for univoltine insects and often complicates the taxonomic assignment of fossil species to modern higher taxa, e.g., to families
Summary
Trichoptera Kirby, 1815 in Burmese amber have been shown to include several morphological features not present in extant species (Wichard & Wang 2017; Wichard et al 2018). The three new species of fossil caddisflies described here are here assigned to two separate families, Odontoceridae Wallengren, 1891 and Calamatoceridae Ulmer, 1905, despite sharing one striking autapomorphy, namely bipectinate antennae, not found in any extant taxa. Marilia Muller, 1880 and two of the extinct genera, Electrocerum Ulmer, 1912 and Electropsilotes Ulmer, 1912, are known from Eocene Baltic amber (Ulmer 1912; Wichard 2009). The other extinct genus, Palaeopsilotreta Wichard & Wang, 2017, is known from mid-Cretaceous Burmese amber. The fossil species Calamodontus grandaevus Botosaneanu & Wichard, 1983 from Taimyr amber in Siberia and Phenacopsyche vexans Cockerell, 1909 from the Florissant Formation in Colorado, each possibly belonging to the family Odontoceridae, are based only on wing fragments and cannot be associated with Odontoceridae with certainty
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
