Mottle-backed Elaenia

Here the details of the Mottle-backed Elaenia named bird below:

SCI Name:  Elaenia gigas
Protonym:  Elainea gigas Proc.Zool.Soc.London(1870) (1870), Pt3 p.831
Taxonomy:  Passeriformes / Tyrannidae / Elaenia
Taxonomy Code:  mobela1
Type Locality:  Rio Napo, Ecuador.
Author:  Sclater, PL
Publish Year:  1871
IUCN Status:  Least Concern

DEFINITIONS

ELAENIA
(Tyrannidae; Ϯ Yellow-bellied Elaenia E. flavogaster) Gr. ελαινεος elaineos  of olive-oil, oleaginous  < ελαια elaia  olive; "Elænia n. g. ⁶)  Musc. pagana Licht.; brevirostris, — modesta, — aurifrons Pr. Max; — Hylophilus cinerascens ejusd.  Numerosæ americanæ, transitum ad Tyrannides præbentes; Fringillis subsimiles.   ...    ⁶) Rostrum crassiusculum, breve, basi dilatatum, altitudine latius; carina dorsali subacuta, sutura recta.  Membrana narium plumulis tecta.  Vibrissæ tenues.  Alæ mediocres vel sub-breves, rotundatæ, remigib. 3-5 reliqvis longioribus.  Pedes mediocres, digitis brevibus, subliberis.  Olivaceæ-cinerascentes; sæpe subtus, interdum vertice flavæ. — Eλαινιος, oleagineus." (Sundevall 1836); "Elaenia Sundevall, 1836, Vetensk. Akad. Handl., 1835, p. 89. Type, by subsequent designation (Gray, 1855, Cat. Gen. Subgen. Birds, p. 49), Muscicapa pagana Lichtenstein = Pipra flavogaster Thunberg." (Traylor in Peters, 1979, VIII, pp. 26-27).  
Var. Elaenea, Elainea, Elainia, Eloenia, Elana, Elania.

gigas
L. gigas, gigantis  giant  < Gr. γιγας gigas, γιγαντος gigantos  giant.
● ex Ardea scolopacea J. Gmelin, 1789, and “Caráu” of de Azara 1802-1805, no. 366 (syn. Aramus guarauna).
● ex “Coucal Géant” of Levaillant 1807, pl. 223 (syn. Centropus phasianinus).
● ex “Touraco Géant” of Levaillant 1813-1818, pl. 19 (syn. Corythaeola cristata).
● ex “Coucou verdâtre de Madagascar” of de Buffon 1770-1785, and “Great Madagascar Cuckow” of Latham 1781 (Coua).
● ex “Plus grand Martin-pêcheur” of de Buffon 1770-1785, and “Great Brown Kingsfisher” of Latham 1782 (syn. Dacelo novaeguineae).