Orites

Abstract: Proteaceae are restricted to the Southern Hemisphere, and of the seven tribes of the subfamily Grevilleoideae, only three (Macadamieae, Oriteae, and Embothrieae) have living members in Argentina. Megafossil genera of Proteaceae recorded from Patagonia includeLomatia, Embothrium, Orites, andRoupala. In this report, we evaluate and revise fossil Argentine Proteaceae on the basis of type material and new specimens. The new collections come from the Tufolitas Laguna del Hunco (early Eocene, Chubut Province), the Ventana (middle Eocene, Rio Negro Province), and the Rio Nirihuau (late Oligocene-early Miocene, Rio Negro Province) formations, Patagonia, Argentina. We confirm the presence ofLomatia preferruginea Berry,L. occidentalis (Berry) Frenguelli,L. patagonica Frenguelli,Roupala patagonica Durango de Cabrera et Romero, andOrites bivascularis Romero, Dibbern et Gandolfo. Fossils assigned toEmbothrium precoccineum Berry andE. pregrandiflorum Berry are doubtful, and new material is necessary to confirm the presence of this genus in the fossil record of Patagonia. A putative new fossil species of Proteaceae is presented as Proteaceae gen. et sp. indet. Fossil Proteaceae are compared with modern genera, and an identification key for the fossil leaf species is presented. Doubtful historical records of Proteaceae fossils for the Antarctic Peninsula region and Patagonia are also discussed. Based on this revision, the three tribes of Proteaceae found today in Argentina were already present in Patagonia by the early Eocene, where they probably arrived via the Australia-Antarctica-South America connection.

Abstract: About 10 taxa of Proteaceae are known from the Early Eocene in Tasmania, one from a Late Eocene site, 22 from four Early Oligocene sites, one from a Late Oligocene-Early Miocene site, 12 or 13 from two Early Pleistocene sites, and five or six from the Middle and Late Pleistocene. Most of the Tertiary fossils are of extinct species, but the extant species Lomatia fraxinifolia and Telopea truncata as well as apparent close relatives of the subalpine rainforest species Orites milliganii, and the subtropical rainforest species O. excelsa have been recorded from the Early Oligocene. None of the Early Oligocene species are known from more than one site, implying very high regional diversity, and floristic differentiation among the sites. High diversity of Proteaceae at some sites may be associated with oligotrophic soils. There is no evidence of any of the modern species-rich scleromorphic groups of Proteaceae except Banksiinae. Scleromorphy was well established in Oriteae, Embothrieae and Banksiinae by the Early Oligocene. The Early Eocene fossils have very small stomata, sparsely distributed on the leaf, which may have been due to elevated atmospheric CO2. All extant Tasmanian genera and many extant species as well as some extinct species were present by the Early Pleistocene. The specific diversity within the region was probably higher than it is now. In order to resolve a nomenclatural problem within the genus Proteaciphyllum, Euproteaciphyllum G.J.Jord., R.J.Carp and R.S.HilI, gen. nov. is proposed and this name is applied to 10 previously described species, The Tasmanian fossil taxa include three new records, and nine new species: Euproteaciphyllum brookerensis G.J.Jord., R.J.Carp. and R.S.HilI, sp. nov., and E. tasmanicum G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov. from Early Eocene sediments; and Orites milliganoides G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov., O. scleromorpha G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov., E. papillosum G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov., E. polymorphum G.J.Jord., R.J. Carp. and R.S,HilI, sp. nov., E. microlobium G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov., E. falcatum G.J.Jord., R.J.Carp. and R.S.HilI, sp. nov., and E. serratum G.J.Jord., R.J.Carp. and R.S.Hill, sp. nov. from Early Oligocene sediments.

Abstract: Proteaceous leaves from two Early Tertiary sites in Tasmania are described and discussed. Based on gross leaf morphological and cuticular characters, 15 species are recognised from Oligocene lacustrine sediments at Cethana. Specimens of two taxa are not distinguishable from the extant species Telopea truncata from Tasmania and Lomatia fraxinifolia from north-eastern Queensland, and are therefore assigned to these species. Two new species of Banksieaephyllum are recognised. Ten other taxa are difficult to identify to existing genera, and are therefore referred to a new genus Proteaciphyllum. They all possess features typical of subfamily Grevilleoideae. Other, less well preserved, but probable Proteaceae from Cethana are also described. Specimens from the Leven River deposit, probably also of Oligocene age, are assigned to a new species of Orites, O. excelsoides. This species is closely related to extant O. excelsa from rainforests of north-eastern New South Wales and north-eastern Queensland. Cethana has by far the highest diversity of Proteaceae of any fossil flora described to date. The fossils also demonstrate the past association of now geographically remote taxa, and the prevalence of sclero- and xero-morphy in the family by the Oligocene.

Abstract: The American Proteaceae are outliers from the main centres of diversity of the family in Australia and South Africa. There are about 83 species in eight genera which all belong to the monophyletic subfamily Grevilleoideae. Three genera, Embothrium, Oreocallis and Lomatia, are placed in the tribe Embothrieae (sensu Johnson and Briggs), four Euplassa, Gevuina, Panopsis and Roupala in the Macadamieae and the single genus Orites in the Oriteae. There are five genera endemic to America and three also have species in Australia and New Guinea (Gevuina, Lomatia and Orites). The Proteaceae appear to have arrived in South America via two routes. The larger genera Euplassa, Panopsis and Roupala, which are all endemic to America and have a general distribution in northern South America and south-eastern Brazil, are derived from Gondwanaland before it separated from South America. The remaining genera are distributed either in temperate South America or in the high Andes and appear to have arrived more recently via the Australia–Antarctica–South American connection. Three of these genera have species in both regions. The centres of species diversity of Euplassa, Panopsis and Roupala fall outside hypothesised forest refugia, indicating that they are not true rainforest species but species of seasonal habitats like those achieved at higher altitudes where they are commonly found. Two genera,Panopsis and Roupala, have reached Central America after the central American land bridge was formed six million years ago. The exact relationship to genera on other continents is still unclear and there is a need for a cladistic biogeographic analysis of the group based on both morphological and molecular data.