In Greek mythology, Gelanor (Ancient Greek Γελάνωρ; also called Pelasgus) was an Inachid king of Argos, son of Sthenelas, and the last ruler of the Crotopid line before Danaus. Apollodorus says he surrendered the kingdom; Pausanias preserves a popular judgment decided when a wolf overcame a bull — read as an omen that Danaus should reign — after which Danaus founded the sanctuary of Apollo Lycius.
Adapted from Wikipedia, "Pelasgus (king of Argos)" and "Danaus" · CC BY-SA 4.0
I.Last Crotopid at Argos
Pausanias' Argive king-list places Gelanor son of Sthenelas (himself son of Crotopus) on the throne when Danaus sailed from Egypt and ended the succession of Agenor's descendants. Apollodorus (Bibliotheca 2.1.4) states more briefly that Gelanor surrendered the kingdom to Danaus, who then named the inhabitants Danaoi after himself.
II.The wolf and the bull
Pausanias (2.19.3–4) tells that Danaus claimed the kingdom against Gelanor before the people; both sides argued plausibly, so judgment was deferred. At dawn a wolf attacked the lead bull of a herd pasturing before the wall and prevailed. The Argives likened Gelanor to the bull and Danaus to the wolf — a stranger who had not yet lived among them — and awarded the kingdom to Danaus. Believing Apollo had sent the wolf, Danaus founded the sanctuary of Apollo Lycius (Wolf-god) at Argos.
III.Aeschylus and the name Pelasgus
In Aeschylus' Suppliants the Danaids seek asylum from King Pelasgus of Argos, child of Palaechthon. Later handbooks identify that welcoming king with Gelanor; the atlas entry keeps the Apollodorus–Pausanias Gelanor as the succession figure who yields to Danaus, while noting the tragic Pelasgus as the same Inachid throne under another name.