Kleine Pauly s.v. Sosiphanes 1 & 2; OCD4 s.v. Sosiphanes; TrGF 1(2).261-263, 280. This Suda entry confuses two men called Sosiphanes, in particular their respective dates. The chronological difficulties are worsened by the appearance of two Sosiphanes also on the Marmor Parium, whose dates do not align with the dates given here in the Suda. There, one Sosiphanes dies in 313/12 BCE (web address 1), and the other is born (?) in 306/05 (web address 2). Cf. P.M. Fraser, Ptolemaic Alexandria (Oxford 1972) vol.2, p.872 and the further bibliography cited there.
[1] See generally R. Pfeiffer, History of Classical Scholarship (Oxford 1968) pp. 119, 160-161, and P.M. Fraser, op. cit. vol. 1, pp. 619-620. For other members of the tragic ‘Pleiad’, cf. alpha 1127, delta 1169, lambda 827, omicron 253, sigma 860 (the entry which has generated 'he too' in the present one), tau 894, phi 358.
[2] 346(?)-336 (phi 354).
[3] 336-323 (alpha 1121).
[4] 336-333.
[5] 324-321.
[6] This makes no sense as it stands and must be textually corrupt. Adler's apparatus summarises several proposed solutions, of which the simplest (Naeke's) is to to delete oi( de/, producing 'though others write that he reached his floruit in the 114th Olympiad'.