Palynology from “The Jurassic Dinosaur Coast” of Asturias (Lastres Fm., Northwestern Spain): palynostratigraphical and palaeoecological insights

Abundant fossils of vertebrates (mainly footprints and bones of dinosaurs) and numerous invertebrates occur in the Upper Jurassic deposits of the Lastres Formation in the Asturias region, North of Spain. However, no palynological study has been published from this geological formation; therefore, much palaeoenvironmental and palaeoecological information is still unknown. In this study, a total of 62 morphospecies, belonging to 49 different morphogenera were identified, including pollen, spores, algae remains, fungi spores, dinoflagellates, foraminifera, and scolecodonts from four different locations on the Asturian coast. Spores are the dominant group of palynomorphs, both in diversity and abundance, contrasting with the minor diversity of pollen grains. The age of some key taxa indicates that the palynological assemblage cannot be older than the Kimmeridgian, suggesting a Kimmeridgian-Tithonian age. The botanical and environmental affinities of the pollen and spores indicate the presence of different plant assemblages, including plant communities from humid areas such as the margin of rivers and small freshwater ponds that were dominated by bryophytes and ferns, and a coastal plant community that would inhabit arid areas and would be dominated by gymnosperms and some pteridophytes. The SEM analyses of wood remains show the abundance of charcoalified remains suggesting that wildfires were usual in The Dinosaur Coast of Asturias during the Kimmeridgian.Xunta de Galicia | Ref. ED481A-2019/243Xunta de Galicia | Ref. ED481A-2020/175Chinese Academy of Sciences | Ref. XDB26000000Ministerio de Ciencia, Innovación y Universidades | Ref. PGC2018-094034-B-C2

Palynological reconstruction of the habitat and diet of Iguanodon bernissartensis in the Lower Cretaceous Morella Formation, NE Iberian Peninsula

The recent discovery of iguanodontid remains from the new Palau-3 site in the Lower Cretaceous Morella Formation is the most complete non-articulated skeleton of Iguanodon bernissartensis on the NE Iberian Peninsula. To elucidate the paleoenvironment of the Palau-3 site, a palynological analysis was carried out on matrix samples collected from around the skeleton. The palynological assemblage is found to correspond to an upper Barremian age. While the assemblage is composed of bryophytes, pteridophytes, gymnosperms, freshwater algae, dinoflagellate cysts and fungal spores, the palynoflora is mostly dominated by the Cheirolepidiaceae conifer (Classopollis) and Anemiaceae fern (mainly Cicatricosisporites) families. The absence of angiosperm pollen in this flora is also noteworthy, as angiosperm remains have been recorded previously elsewhere in the Morella Formation. At the Palau-3 site, the fronds of Cyatheaceae and Anemiaceae ferns, as well as the foliage of the Cheirolepidiaceae conifers, may have been the major sources of nutrition of I. bernissartensis and other herbivorous iguanodontians. The paleobotany of the four major localities bearing I. bernissartensis remains in western Europe was surveyed to determine the habitat and feeding preferences of this styracosternan dinosaur. These localities are Bernissart (Belgium), Isle of Wight (England), Nehden (Germany), and Morella (Spain). In accordance to this survey, the habitat preferences of I. bernissartensis and association with specific plant communities show that this ornithopod species was adapted to a wide variety of paleoenvironments.Xunta de Galicia | Ref. ED431C-2019/28Xunta de Galicia | Ref. ED481A-2020/175Universidade de Vigo/CISU

Palynostratigraphical review of the K–Pg boundary from the Ibero-Armorican Island: New data from the Maastrichtian dinosaur outcrop Veracruz 1 (Pyrenees, NE Iberian Peninsula)

The palynostratigraphy of the K-Pg boundary interval in SW Europe has been a subject of ongoing debate, despite numerous palynological studies in the region. To address this, we review previous publications and conduct analysis of new deposits to establish a palynostratigraphical chart. A total of 40 palynological studies within the Normapolles palynological province were reexamined to elucidate key taxa restricted to the Cretaceous (K-taxa), to the Maastrichtian-Danian interval (KPg-taxa) and those restricted to the Paleogene (Pg-taxa). Eventually, we propose 18 key taxa to differentiate a Maastrichtian from a Danian palynological assemblage within the Normapolles Province. Afterward, a palynostratigraphical analysis was carried out in Veracruz 1 (Aragonese Pyrenees), one of the more modern dinosaurbearing sites of Europe. The palynological assemblage corresponded to an upper Maastrichtian age and was composed by pteridophyte spores, gymnosperms, angiosperms, dinoflagellate cysts, algae, and fungal spores. It was predominated by angiosperm pollen (Liliaceae, post-Normapolles, and triporate pollen). The plant communities in Veracruz 1 seem to be characterized by plants from an open coastal forest prevailed by Liliaceae flowering herbs and Juglandaceae/Myricaceae dicotyledonous trees and shrubs thriving in temperate-warm paleoclimate. The Gondwanan botanical influence was also supported by the presence of Bacumorphomonocolpites sp., as this taxon was previously recorded in other upper Maastrichtian deposits from Europe.Agencia Estatal de Investigación | Ref. PID2021-122612OB-I00Xunta de Galicia | Ref. ED431C-2019/28Xunta de Galicia | Ref. ED481A-2020/175Universidad Nacional Autónoma de México | Ref. UNAM-DGAPA 2023–2024Swedish Research Council | Ref. VR 2022-03920Universidade de Vigo/CISU

Insect and plant diversity in hot-spring ecosystems during the Jurassic-Cretaceous boundary from Spain (Aguilar Fm., Palencia)

Hydrothermal palaeoenvironments are very uncommon in Upper Jurassic and Lower Cretaceous deposits worldwide. We present new plant and insect remains from travertines formed during the Jurassic-Cretaceous boundary in northern Spain (Aguilar Fm., Palencia province). A total of 136 plant specimens and three insect wings were collected and studied. This entomofauna consists of dragonfly (Odonata) wings including Cymatophlebiidae and an undetermined new genus and species of Aktassiidae, representing the first report of these families for the Iberian Peninsula. The fossil flora shows different morphotypes of plants, which have been tentatively assigned to three different genera. The taphocoenosis of the flora was dominated by Bennettitales (98.5%) including cf. Pterophyllum sp., Ptilophyllum cf. acutifolium, Ptilophyllum cf. pecten, Ptilophyllum cf. pectiniformis and cf. Ptilophyllum sp., and the occasional presence of ferns (1.5%) represented by the taxon Cladophlebis cf. denticulata. The presence of the Anisoptera Cymatophlebia cf. longialata suggests a higher affinity for a Tithonian age of the studied site, and the anatomy and palaeogeographical distribution of this species suggest capacity to migrate for rather long distances. The floristic composition of the site differs remarkably from other Tithonian-Berriasian floras of the Iberian Peninsula. The presence of Odonata and the distinctive flora in (semi)arid conditions could be due to the hot-spring providing an environmental niche with constant conditions of warmth and humidity forming an ‘ecological oasis’.Ministerio de Ciencia, Innovación y Universidades de España | Ref. PGC2018-094034-B-C22Chinese Academy of Sciences | Ref. XDB26000000Xunta de Galicia | Ref. ED481A-2019/243Xunta de Galicia | Ref. ED481A-2020/17

A Robinson Crusoe story in the fossil record: Plant-insect interactions from a Middle Jurassic ephemeral volcanic island (Eastern Spain)

We present here the first record of plant-insect interactions from an ephemeral volcanic island that was placed 150 km away from the nearest continental mass. The island was formed and destroyed during the Aalenian (Middle Jurassic) in a shallow sea of the southwestern Tethyan realm corresponding today to a place located in eastern Spain. These plant-insect interactions were mainly documented in leaves of Cycadophytes (comprising both Cycads and Bennettitales), and they have been described and classified into different Damage Types (DTs) and Functional Feeding Groups (FFGs). The interactions were assigned to 11 different DTs including different types of hole feeding, margin feeding, surface feeding, piercing and sucking, mining(?), and some putative ovipositional scars. The presence of these interactions implies that the island was colonized by different groups of insects, including orders such as Coleoptera, Hemiptera, Odonata, or Lepidoptera. The low variety and incidence of interactions comparing with other Middle Jurassic plant-insect interactions assemblages indicate that the diversity of insects was not high, possibly due to the difficulty of reaching this island by various lineages, the small size of the landmass of the island, and the limited food availability (mainly Cycadophytes). Possible colonization strategies could be by atmospheric dispersion, using floating remains of plants or pterosaurs as vectors, by active flight for Lepidoptera, or by rafting and floating in marine currents for flightless or other insects.Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGAgencia Estatal de Investigación | Ref. PGC2018-094034-B-C22Xunta de Galicia | Ref. ED481A-2019/24

A new uppermost Albian flora from Teruel province, northeastern Spain

This paper reports a new Early Cretaceous flora discovered recently near the village of Estercuel (Teruel province, northeastern Spain). The plant bearing beds belong to the uppermost part of the Early Cretaceous succession, at the top of the fluvial deposits of the Utrillas Formation. The site has yielded a diverse assemblage of plant compressions including lycopods and ferns, various gymnosperms as well as terrestrial and aquatic angiosperms. Leaves of aquatic lycopods (Isoetites sp.) constitute a minor component of the palaeobotanical assemblage. Filicales are not very common, with Dicksoniales (Onychiopsis sp.) and a few specimens of Cladophlebis type fronds. The gymnosperms are represented by fragmented remains of long parallel veined Desmiophyllum leaves as well as a great abundance of conifer axis corresponding to the form-genus Pagiophyllum and female cones. Terrestrial angiosperms include pinnately lobed leaves of the genus Myricompia, simple leaves with spatulate lamina and some petiolate leaves both corresponding to angiosperms of uncertain affinity. Aquatic angiosperms consist of Nelumbo-like floral receptacles (Nelumbonaceae, Proteales) and Aquatifolia cf: fluitans (Nympheales). The palynological assemblage is dominated by pollen of gymnosperms (mainly Taxodiaceaepollenites hiatus, Classopollis major and Araucariacites australis). It also includes many angiosperm grains (Afropollis jardinus, Clavatipollenites spp., Di-chastopollenites spp., Liliacidites doylei, Monosulcites chaloneri, Penetetrapites mollis, Pennipollis spp., Phimopollenites augathellaensis, Retimonocolpites textus, Rousea spp., Senectotetradites varireticulatus, Stellatopollis barghoornii, Striatopollis spp., Transitoripollis sp. cf. T similis, Tricolpites spp., Tricolporoidites sp.) and records the first occurrence of tricolporate forms in the uppermost part of the Utrillas Formation. Both macroflora and microflora assemblages present taxa similar to those of the uppermost Albian Shaftesbury Formation in northwestern Alberta in Canada, the uppermost Albian Denton Shale Member of Bokchito Formation in southern Oklahoma, the lower part of the Upper Albian Dakota Formation from the mid-west of North America, and Subzone II C of the Potomac Group, eastern United States. Both macro- and microflora assemblages display boreal influence with some similar taxa to those of the Upper Albian Kome Formation in western Greenland and some taxa as Afropollis jardinus and Stellatopollis barghoornii more frequently found in the tethyan and gondwanan realms. A gondwanan affinity is also indicated by the presence of Klitzschophyllites leaves

Palynological and sedimentological implications of the sauropterygian Upper Triassic site of El Atance (Central Iberian Peninsula)

This study presents new palynological and sedimentological data concerning the Upper Triassic outcrop El Atance (Guadalajara province, Spain). This fossil site has provided a unique and unprecedented concentration of reptile skeletons from the Late Triassic in the Iberian Peninsula, which are almost complete, articulated and preserved in three dimensions. It is the type locality of the simosaurid nothosauroid Paludidraco multidentatus and the henodontid placodont Parahenodus atancensis, being the only species of these clades represented with some certainty in the Iberian record. Although these reptiles are often linked to shallow marine environments, little is known about the sedimentary environment where they became fossilized. Furthermore, to compare these remains with those from other areas of Europe, greater precision in their age assignment is necessary.The new palynological data provided in this study allows us to assign a precise age, in addition to other data such as a probable plant community, palaeoecology, and palaeoclimatic conditions. This information together with the geological and sedimentological data and the new isolated sauropterygian remains studied, allow a better understanding of the local palaeogeography and the evolutionary history of the vertebrates found in the El Atance fossil site.Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGXunta de Galicia | Ref. ED431C-2019/28Ministerio de Ciencia, Innovación y Universidades | Ref. PGC2018-098272-B-10