Heteragrion muryense Costa & Santos, 2000

(Figs. 51a–d)

[Key locator: Key to Group A species, couplet 19 (2’)]

Heteragrion muryense: Costa & Santos 2000: 1–8 (description and diagnosis of ♁ and ♀; key to species of Heteragrion recorded to Rio de Janeiro state, ♁ in couplet 2’; figs. 1–8);— Lencioni 2005: 136 (data on description and distribution, illustration from Costa & Santos 2000; figs. 85a–h);— Machado & Bedê 2006: 50–52 (differences from H. tiradentense, H. petiense, H. flavovittatum and H. ovatum);— Garrison et al. 2010: 88 (list of Heteragrion species);— Lencioni 2013: 12 (synonymic list, types, distribution, diagnosis; figs. 20–21, 36a–c, 45a–c, 48a–b, 53a–b, 68);— Lencioni 2017: 151–152 (general taxonomic information; distribution; figs. 75–76);—Ávila-Jr. et al. 2020: 121–130 (comparison with H. itacolomii).

Material examined. 2♁♁ BRAZIL, Rio de Janeiro state, Nova Friburgo, Pico São João, 26.i.1996, (type locality, 1500m asl), Mielke leg., ABMM .

Known distribution. Brazil (Nova Friburgo, Rio de Janeiro state).

Diagnosis and remarks. This is a very rare and unique species, which has been collected on only two occasions (1990 and 1996), not seen ever since, and assessed as Data Deficient in the IUCN Red List (Vilela & Guillermo-Ferreira 2021h). The following character combination distinguishes this species from the remainder of Group A species: BP uniquely consisted of a long, narrow ventral branch (Fig. 51c–d); upper plate small, shaped like an inverted triangle, bearing a small row of teeth posteriorly; ridge fused with ML up to 1/2 of lower plate (Figs. 51c–d).