Engelhardia macroptera

Engelhardia macroptera whole - plant

Engelhardia (sect. Palaeocarya) macroptera (BRONGNIART) UNGER (fruit); Engelhardia orsbergensis (P.WESSEL et C.O.WEBER) JÄHNICHEN, MAI et H.WALTHER (leaf); Engelhardia (pollen) Pl. 1, Figs 8–11

M a t e r i a l. Fruit bracts from the Messinian of Monte Tondo ( 2 specimens) and Tossignano (5), from the Pliocene of Meleto (1) and Valle del Salto (1). Several fruits without bracts from two Zanclean localities: Ca’ Viettone and Sento. Leaflets from the pre-evaporitic Messinian of Pollenzo ( Bertini and Martinetto 2014: 1 specimen, lost), Palena ( Teodoridis et al. 2015a: 1 specimen), the Damarco bed of the evaporitic Messinian of Govone ( 3 specimens, Palaeontological Museum of Astigiano and Monferrato). Pollen grains of Engelhardia are frequent in several Messinian and Zanclean sites, but less abundant in the Piacenzian ( Bertoldi 1988, 1996, Bertoldi et al. 1994, Bertoldi and Martinetto 1995, Bertini 2010 and references therein).

R e m a r k s. The attribution to the living genus Engelhardia of rare fruits, fruit-bracts, leaves, and more frequently pollen, found scattered in several Italian sites of different ages, is the basis for the formulation of an Engelhardia macroptera Whole-Plant Concept for the Neogene of Italy, according to the line of evidence ISA. The fruits are small thin walled nuts, represented in the sandy sediments of a few Pliocene sites by just 1 to 3 specimens, isolated from any other Engelhardia remains, being more abundant only at the Ca’ Viettone site ( Martinetto and Vassio 2010, Martinetto et al. 2018). In fine-grained sediments the nuts are sometimes accompanied by characteristic involucres consisting of three apical triveined lobes and one basal, opposite small lobe enveloping the nut ( 3 to 5 mm in diameter). In Italy the involucres have been reported from Messinian ( Bertini and Martinetto 2008) and Pliocene sites ( Fischer and Butzmann 2000), as well as from Valle del Salto, a site of uncertain Pliocene or Pleistocene age ( Chiarini et al. 2009). Similar fruits in the European Oligocene and Miocene are accompanied by leaflets with finely serrate margins and a sessile asymmetrical base, which are assigned to Engelhardia orsbergensis ( Kvaček 2007, Teodoridis et al. 2015b). In Italy only a few leaflet specimens were reported, often with uncertain identification ( Bertini and Martinetto 2014, Teodoridis et al. 2015a, Cimino et al. 2016). In this paper we confirm the occurrence of leaflets in the Damarco bed of Govone ( Cimino et al. 2016) because of two new specimens that show diagnostic characters pointing to Engelhardia orsbergensis . Pollen grains identified as “ Engelhardia ” ( Bertini 2010, Magri et al. 2017 and references therein) or “ Engelhardia / Platycarya - type ” ( Bertoldi 1988, 1996, Bertoldi et al. 1994, Bertoldi and Martinetto 1995) can be tentatively referred to the same whole-plant on the basis of the line of evidence ISA.

Because all the members of the Engelhardia phylogenetic clade ( Zhang et al. 2013), including Alfaroa and Oreomummea, are trees of medium to large height, with opposite deciduous imparipinnate leaves and catkins of centimetre-sized nut-bearing bracts, the fossil Engelhardia macroptera whole-plant would also share this kind of habitus.