Thursday, May 21, 2020

[PaleoEntomology • 2020] Morrisonnepa jurassica • First Fossil True Water Bugs (Heteroptera, Nepomorpha) from Upper Jurassic strata of North America (Morrison Formation, southeastern Utah)

 Morrisonnepa jurassica  
Lara, Foster, Kirkland & Howells, 2020.

The first fossil hemipteran from the Late Jurassic of North America, Morrisonnepa jurassica n. gen. et n. sp., is reported and described from the Morrison Formation, Jurassic Salad Bar locality, San Juan County, Utah, USA. The new specimen is characterised and illustrated, showing morphological characters similar to nepomorphs such as forewing well-developed and folded flat on the abdomen, oval abdomen shape, and the presence of a short pair of appendages. The taxonomic allocation close to members of the Nepomorpha is discussed. Morrisonnepa jurassica n. gen. et n. sp. was collected with abundant plants, spinicaudatan carapaces, and a small amphibian from a finely laminated shale that overlies a coarser plant debris bed, supporting the presence of a possible oxbow lake or pond, environments developed within the greater ecosystem of the Morrison Formation during the Late Jurassic. In this context, we analyse the taphonomic and palaeoecological implications of the presence of aquatic insects. Besides providing morphological information on Jurassic nepomorphs, the new fossil helps illustrate how the aquatic insect assemblage was integrated during the Jurassic in North America.

KEYWORDS: Heteroptera, Nepomorpha, Late Jurassic, Morrison Formation, North America (Utah)

Systematic palaeontology

Order: HEMIPTERA Linneaus (1758)
Suborder: HETEROPTERA Latreille (1810)
Infraorder: NEPOMORPHA Popov (1968)

Family: Incertae Sedis

Genus: Morrisonnepa Lara, Foster, Kirkland, and Howells, n. gen.

Derivation of name: The generic name derives from the Morrison Formation, and –nepa, a standard suffix used for the superfamily Nepoidea.

 Morrisonnepa jurassica Lara, Foster, Kirkland, and Howells, n. sp. 

Derivation of name: The specific name jurassica refers to Jurassic Period from which the species is derived.

María B. Lara, John R. Foster, James I. Kirkland and Thomas F. Howells. 2020. First Fossil True Water Bugs (Heteroptera, Nepomorpha) from Upper Jurassic strata of North America (Morrison Formation, southeastern Utah). Historical Biology: An International Journal of PaleobiologyDOI: 10.1080/08912963.2020.1755283