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- Eurya stigmosa (Theaceae), a new and extinct record for the Calabrian stage of Madeira Island (Portugal): 40Ar/39Ar dating, palaeoecological and oceanic island palaeobiogeographical implicationsPublication . Góis-Marques, Carlos A.; Mitchell, Ria L.; Nascimento, Lea de; Fernández-Palacios, José María; Madeira, José; Sequeira, Miguel Menezes deThe general dynamic model of oceanic island biogeography (GDM) predicts the immigration, speciation and extinction of terrestrial biota through geological time on oceanic islands. Additionally, the glacial sensitive model of island biogeography (GSM) also predicts extinction due to eustatic and climate change within islands. However, well-documented and natural pre-Holocene plant extinctions are almost unknown for oceanic islands worldwide. To test these predictions, we have sampled the Early Pleistocene Porto da Cruz lacustrine and fluvial sediments for plant fossils that could confirm the GDM and GSM extinction predictions. Additionally, two new 40Ar/39Ar geochronological analyses were per formed, constraining the age of the sediments to 1.3 Ma (Calabrian). Among the fossils, Eurya stigmosa (R.Ludw.) Mai (Theaceae) seeds were recognised and studied by scanning electron microscopy (SEM). E. stigmosa is the first report of a natural (non-anthropogenic) extinct plant in the fossil record for Madeira Island, and for an oceanic island, confirming the GDM and GSM predictions. Eurya spp. palae obiogeography indicates wider distribution in Europe until the end of the Pliocene (2.58 Ma), becoming extirpated to small refugia and extinct thereafter. The Madeiran record expands the formerly unknown presence of E. stigmosa to the Macaronesian realm. The new dating of the deposit at 1.3 Ma (Calabrian) means that E. stigmosa in Madeira was already in a refugium. The extinction in Madeira is most probably a combination of island ontogeny and climate change due to Pleistocene glaciations. The palaeoecological role of this extinct shrub or tree is currently unknown, but it was a probably an element of the Madeiran laurel forest, as this community was already present in Madeira at least 1.8 My ago. This new information corroborates the predictive power of GDM and GSM and adds a new view on the importance of studying oceanic island palaeobotany, specially palaeocarpofloras.
- The Quaternary plant fossil record from the volcanic Azores Archipelago (Portugal, North Atlantic Ocean): a reviewPublication . Góis-Marques, Carlos A.; Nascimento, Lea de; Sequeira, Miguel Menezes de; Fernández-Palacios, José María; Madeira, JoséPlant fossils are known from the Azores Islands, yet poorly studied. We present a comprehensive bibliographical review for the archipelago. A first pre-scientific reference dates from late fifteenth century, while the first scientific description was reported in 1821, accounting for trunks in pyroclastic units and silicified plants within hydrothermal deposits. Throughout the second-half of the nineteenth century and the first-half of the twentieth century, prospection by naturalists and geological mapping work, led to the discovery and description of plant fossils in most islands. From the 1970s onwards, the taxonomic interest ceased, and plant fossils were used mainly for 14C dating. Recently, sediment cores from lakes and peatlands were used for palaeoecological reconstructions and to measure anthropogenic impacts. Generally, plant fossils are younger than 50 ka, although older fossils may exist. Azorean plant fossils include somatofossils of leaves, stems, logs and seeds preserved as impressions, compressions, adpressions, permineralizations, lava tree casts and mummifications. The taphonomy of macrofloral elements is usually related to explosive volcanic activity, while palynological record is associated with lake sediments and peat bogs. The persistence in palaeobotanical and palaeopalynological studies will decisively contribute to disentangle the paleodiversity, palaeoecology, and add crucial information on insular plant phylogeny and biogeography.
- Climate change and human impact in MacaronesiaPublication . Fernández-Palacios, José María; Nogué, S; Criado, C; Connor, S; Góis-Marques, Carlos; Sequeira, M.; Nascimento, L.
- The first Ichneumonid fossil from the Early Pleistocene of Madeira Island (Portugal)Publication . Góis-Marques, Carlos A.; Jesus, José; Sequeira, Miguel Menezes; Madeira, JoséIn oceanic islands, well age-constrained deposits containing arthropod somatofossils (body fossils) are rare. However, when available, these are important for providing empirical and independent minimum ages for molecular phy logenetic dating and complementary data on taxonomy, evolution and palaeobiogeography information of the biological groups found as fossils. This is especially important for taxa that speciated within oceanic islands, many becoming single island endemics (SIE). Recently, associated with a 1.3 Ma (Calabrian) fluvial and lacustrine sedimentary deposit from Porto da Cruz in Madeira Island (Fig. 1), a wing, putatively identified as Hymenoptera, was found. Here we describe this wing fossil as belonging to Ichneumonidae, a group with ca. 30% of SIE in Madeira Island. Moreover, this is the first somatofossil of ichneumonid parasitic wasps found in Madeira Island and in Macaronesian islands (i.e. Azores, Madeira, Canaries and Cabo Verde). Since the 19th century, oceanic island attracted several naturalists due to the high probability of finding taxonomical novelties (e.g. Vieira, 2005). Darwin (1859) amplified this interest, as oceanic islands biota presented a central role to explain evolution. Today oceanic islands became the ideal locations to study evolution, biogeography and ecology (e.g. Whittaker et al., 2017). Madeira Island (Central Atlantic Ocean; Fig. 1), geologically a shield volcano of 7 Ma (Ramalho et al., 2015 and references therein), is considered an insect diversity hotspot where 3019 species and subspecies are known, of which 665 are SIE (Borges et al., 2008). This diversity is most probably explained by stepping-stone through palaeo-Macaronesian islands and isolation (Triantis et al., 2010; Fernández-Palacios et al., 2011). Palaeoentomological records are rare in Madeira. The only known record is from the Mio-Pleistocene deposit of São Jorge (see Góis-Marques et al., 2018), where Heer (1857) described an extinct coleopteran, Laparocerus wollastoni, based on fossilized elytra. Machado (2006) in a taxonomic review of Laparocerus considers this taxon as nomen dubium, due to the missing holotype and the impossibility of reapraising its taxonomy. On other Macaronesian archipelagos, espe cially in the Canaries Islands, several deposits with insect ichnofossils have been described (e.g. Edwards & Meco, 2000; Meco et al., 2011; La Roche et al., 2014). In Azores only xylophagous ichnoentomological traces in charcoal wood are known (Góis-Marques et al., 2019b). The fossil wing was found within laminated lacustrine fine sandstone, associated with plant fossils. The sediments are constrained by two 40Ar-39Ar dates to 1.3 Ma, Calabrian stage (Góis-Marques et al., 2019a). Fossils are kept in the palaeobotanical collection at the Madeira University herbarium (UMad-P) with the numbers UMad-P500a (part) and UMad-P500b (counter-part). The wing fossil was studied under a stereo microscope, and its identification was performed through several sources (e.g. Goulet & Huber, 1993) and specific guidebooks (Prehn & Raper, 2016). Wing description follows the Comstock-Needham system as described by Quicke (2015)
- Inventory and review of the Mio–Pleistocene São Jorge flora (Madeira Island, Portugal): palaeoecological and biogeographical implicationsPublication . Góis-Marques, Carlos A.; Madeira, José; Sequeira, Miguel Menezes deThe occurrence of plant fossils on Madeira Island has been known since the mid-nineteenth century. Charles Lyell and George Hartung discovered a leaf bed rich in Lauraceae and fern fossils at S~ao Jorge in 1854. The determinations were controversial but a full review was never performed. Here we propose possible geological settings for the fossiliferous outcrop, and present an inventory and a systematic review of the surviving specimens of the S~ao Jorge macroflora. The S~ao Jorge leaf bed no longer outcrops due to a landslide in 1865. It was possible to establish the two alternative volcano stratigraphical settings in the sedimentary intercalations from the Middle Volcanic Complex, ranging in age from 7 to 1.8 Ma. The descriptions of Heer (1857), Bunbury (1859) and Hartung & Mayer (1864) are reviewed based on 82 surviving specimens. From the initial 37 taxa, we recognize only 20: Osmunda sp., Pteridium aquilinum, Asplenium cf. onopteris, aff. Asplenium, cf. Polystichum, cf. Davallia, Woodwardia radicans, Filicopsida gen. et sp. indet. 1 and 2, Ocotea foetens, Salix sp., Erica arborea, cf. Vaccinium, Rubus sp, cf. Myrtus, Magnoliopsida gen. et sp. indet. 1 to 3, Liliopsida gen. et sp. indet. 1. Magnoliopsida gen. et sp. indet. 4 is based on one previously undescribed flower or fruit. The floristic composition of the S~ao Jorge fossils resembles the current floristic association of temperate stink laurel (Ocotea foetens) forest, suggesting a warm and humid palaeoclimate and indicating that laurel forests were present in Macaronesia at least since the Gelasian, a time when the palaeotropical geofloral elements were almost extinct in Europe.
- Darwin, Hooker and Arruda Furtado and the palaeobotany of Azores: Rediscovering the first collectionsPublication . Marques, Carlos A. Góis; Sequeira, Miguel Menezes deThe historical investigation of the palaeobotany of the Azores Islands led to the recent rediscovery of the leaf fos sils initially collected by Arruda Furtado in the late 19th century. Advised by Sir Charles Darwin and Sir Joseph Dalton Hooker to search for plant fossils, Arruda Furtado found the first specimens in São Miguel Island, and sent them to the UK for further identification. A recent search at the Natural History Museum, UK, revealed that from a total of sixteen specimens, only one specimen survived. In the same tray, two undescribed specimens from Furnas (São Miguel) were found. Here we describe and identify them as Woodwardia radicans, Laurus azorica and an unidentified fern. The taphonomy indicates that these fossils were preserved in a trachytic tuff, possibly related to the explosive episodes of the Furnas volcano, indicating that they could be late Pleistocene to Holocene in age. This report aims to highlight the potential of future palaeobotanical studies of the Azores Islands.