Događaj Selli, poznat i kao OAE1a, bio je jedan od dva okeanska anoksijska događaja u razdoblju kreda (period) krede, koji su se dogodili prije oko 120 miliona godina i trajali otprilike 1 do 1,3 miliona godina.[1][2]Aptijsko izumiranje bilo je malih razmjera, a pretpostavlja se da se zbilo prije oko 116 do 117 miliona godina.[3]
^{{Cite journal last=Li first=Yong-Xiang last2=BraDonji first2=Timothy J. last3=Montañez first3=Isabel P. last4=Osleger first4=David A. last5=Arthur first5=Michael A. last6=Bice first6=David M. last7=Herbert first7=Timothy D. last8=Erba first8=Elisabetta last9=Premoli Silva first9=Isabella date=15. 7. 2008 title=Toward an orbital chronology for the early Aptian Oceanic Anoxic Event (OAE1a, ~ 120 Ma) journal=Earth and Planetary Science Letters volume=271 issue=1–4 pages=88–100 doi=10.1016/j.epsl.2008.03.055 bibcode=2008E&PSL.271...88L}}
^{{cite journal author = Leckie, R. author2=BraDonji, T. author3=Cashman, R. year = 2002 title = Oceanic anoxic events and plankton evolution: Biotic response to tectonic forcing during the mid-Cretaceous journal = Paleoceanography volume = 17 issue = 3 pages = 1–29 url= https://www.geo.umass.edu/faculty/leckie/Leckie%20et%20al.%202002.pdf doi = 10.1029/2001pa000623 bibcode =2002PalOc..17.1041L}}