New Cretaceous records and the diversification of crown-group ants (Hymenoptera: Formicidae)
Résumé
The knowledge on Cretaceous ants has significantly improved
within the last decade, thanks to increasing discoveries from insect-
rich amber deposits. Yet, the vast majority of fossils found preserved
in Cretaceous deposits belongs to extinct, stem-group ants such as the
Sphecomyrminae and Brownimeciinae. To date, only nine species in
eight genera have been attributed to crown-group ants. Among these,
however, Burmomyrma rossi Dlussky, 1996 should be excluded from
Formicidae and transferred to Falsiformicidae (Chrysidoidea). Also,
the placement of three species from Campanian Canadian amber is
still debatable: Canapone dentata Dlussky, 1999, originally placed in
Ponerinae and later transferred to Ectatomminae; Eotapinoma macalpini
Dlussky, 1999 in Dolichoderinae; and Cananeuretus occidentalis Engel
& Grimaldi, 2005 in Aneuretinae. The three species were each based on
a unique specimen that was only partial or partly visible, two of which
have been lost, and their precise affinity remains enigmatic. Similarly,
imprint fossils from the Turonian of Botswana, that were tentatively
placed in Ponerinae (Afropone oculata and A. orapa Dlussky, Brothers
& Rasnitsyn, 2004) and Myrmicinae (Afromyrma petrosa Dlussky,
Brothers & Rasnitsyn, 2004), were based on poorly preserved specimens
and assignment to these subfamilies has been questioned. Finally, only
two of the nine described species are definitely assignable to extant
subfamilies: Kyromyrma neffi Grimaldi & Agosti, 2000, a Formicinae
from Turonian Raritan amber; and Chronomyrmex medicinehatensis
McKellar, Glasier & Engel, 2013, a Dolichoderinae from Canadian
amber. Here I present six new morphotypes from Burmese amber
that are assignable to crown ants: a Ponerinae, a Formicinae, and a
Dolichoderinae in early Cenomanian amber from Northern Myanmar
(‘Kachin amber’); and a Ponerine and two Dolichoderinae in late
Campanian amber from Central Myanmar (‘Tilin amber’). These
records greatly expand the known diversity of Cretaceous crown ants,
and shed a new light on the origin and early diversification of extant ant
subfamilies prior to their great Cenozoic expansion.
(PDF) New Cretaceous records and the diversification of crown-group ants (Hymenoptera: Formicidae). Available from: https://www.researchgate.net/publication/332622719_New_Cretaceous_records_and_the_diversification_of_crown-group_ants_Hymenoptera_Formicidae [accessed May 21 2019].