Specimens of a new fruit genus and species, Alatonucula ignis, from the early Eocene Laguna del Hunco flora of Chubut, Patagonia, Argentina, have characteristics consistent with assignment to Juglandaceae. Each fossil fruit consists of a nutlet with an attached wing that varies from unlobed to trilobed. One specimen clearly shows that the nutlet has a single locule partially subdivided into four chambers; its counterpart contains a four-lobed locule cast. The basally partitioned locule with lobed seed indicates that Alatonucula can be placed within Juglandaceae; the overall structure of the fruits suggests affinities to subfamily Engelhardioideae, which typically have fruits consisting of a nutlet attached to a trilobed wing. Parsimony analyses of a morphological matrix for extant and fossil Juglandaceae revised from a previously published study demonstrate that 1) Alatonucula groups with Engelhardioideae; and 2) Paleooreomunnea, an Eocene North American taxon that includes a fruit type with a trilobed wing, is within crown-group Engelhardioideae. Alatonucula, along with fossil juglandaceous pollen from the Paleogene of Patagonia, indicates that Juglandaceae may have had an unexpectedly early presence in South America. Furthermore, these fruits represent a Laurasian biogeographic signal in the Laguna del Hunco flora, which contrasts with the predominantly Australasian signal highlighted in previous studies.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 41 • No. 2