Recent revisions of the taxonomy of genus Mobula included the decision to consider the circumglobal Spinetail Devil Ray M. japanica (Müller & Henle, 1841) a junior synonym of the Mediterranean Giant Devil Ray M. mobular (Bonnaterre, 1788), causing M. mobular to become a circumglobal species (Poortvliet et al. 2015, Hosegood et al. 2018, White et al. 2018).Notarbartolo di Sciara et al. (2020) argued that one of the traits that were used to support the differentiation between the two species, the maximum size of M. mobular purportedly in excess of 5 m disc width (DW), can be explained by past misidentifications of M. birostris, and therefore unsubstantiated. This also supports their recommendation to retain for the species the common name Spinetail Devil Ray instead of Giant Devil Ray.

Anthus similis and A. nyassae (del Hoyo and Collar 2016) were previously lumped as A. similis following AERC TAC (2003); Cramp and Simmons (1977-1994); Dowsett and Forbes-Watson (1993). Anthus longicaudatus is no longer recognized as a species, following del Hoyo and Collar (2016); available material in museums is an amalgam of specimens of A. vaalensis and A. similis.

Riparia riparia and R. diluta (del Hoyo and Collar 2016) were previously lumped as R. riparia following AERC TAC (2003), AOU (1998 and supplements), Cramp and Simmons;(1977-“1994), Dowsett and Forbes-Watson (1993), SACC (2005 and updates), Sibley and Monroe (1990, 1993), and Stotz et al. (1996).

Aetomylaeus caerulofasciatus has recently been described as distinct from the wider-ranging Indo-West Pacific A. nichofii (White et al. 2015).

Aetobatus ocellatus (Kuhl, 1823) was previously considered to be an Indo-West and Central Pacific form of the wider ranging Aetobatus narinari (Euphrasen, 1790). Comparative analysis of the morphology, molecular and parasite diversity has resulted in the redescription of A. ocellatus from tropical and warm-temperate waters of the Indian Ocean and West-Central Pacific Ocean with A. narinari being restricted to the Atlantic Ocean (Richards et al. 2009, White et al. 2010). Molecular analyses suggest greater levels of speciation within the Aetobatus genus, with distinguishable groups in the Western Indian Ocean and Northwest Pacific (Schluessel et al. 2010, White et al. 2010). Samples from Qatar cluster separately -- designated as A. cf. ocellatus 2 (D. Ebert pers. comm. 2017). This requires further examination to delineate species boundaries.

Previously placed in Sylvia (del Hoyo and Collar 2016) but moved to current genus following Cai et al. (2019). Until recently considered to constitute several species, with splits of althaea and minula (with margelanica) (Sibley and Monroe 1990, 1993) from curruca (AOU 1998 and supplements; Dowsett and Forbes-Watson 1993; Sibley and Monroe 1990, 1993), and this may ultimately be more appropriate. Nuclear DNA, however, fails to support clades based on mtDNA, and, although althaea is relatively well marked, characters used to define species (and subspecies) limits prove too weak for taxa to pass tests of diagnosability (Olsson et al. 2013b). Treatment of these forms under a single species currently therefore inevitable (Dickinson and Christidis 2014).Geographical variation largely clinal, subspecies halimodendri intergrading widely with nominate in S Siberia. Proposed subspecies caucasica (Turkey, Caucasus and N Iran) and zagrossiensis (SW Iran) barely separable from nominate; similarly, telengitica (Russian Altai and Mongolia) included in margelanica. Proposed subspecies snigirewskii (Turkmenistan) largely inseparable from minula, and jaxartica (S Kazakhstan) falls within range of clinal variation of halimodendri; poorly differentiated chuancheica (upper R Huang He, S of Gobi, in N China) included in margelanica. Birds from Alai and Pamir Ranges E to Tien Shan sometimes separated as subspecies monticola, but not reliably distinguishable from those in rest of range of althaea. Six subspecies recognized.