Eurypyga helia (Pallas 1781) is the extant sunbittern of South America. Here and traditionally it nests with storks like Grus (below), but has shorter legs. It is not related to the kagu (Rhynochetos) of New Caledonia despite wing pattern and DNA studies.

Grus grus (Linneaus 1758; 120 cm long) is the extant common crane. The skull is much shorter than the cervical series. The sternum extends anteriorly along the coracoids. Note pedal digit 4 has only three phalanges. The rail (Rallus) is an ancestor.

Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

Pallas PS 1781. Katalog rasteniyam, nakhodyashchimsya v Moskve v sadu yego prevoskhoditel'stva deystvitel'snogo statskogo sovetnika i Imperatorskogo Vopitatel'nogo doma znamenitogo blagodetelya, Prokofiya Akinfiyevich Demidova, sochinyonnyy P. S. Pallasom, adademikom sankt-peterburgskim (Saint Petersburg, 1781).

wiki/Common_crane
wiki/Sunbittern