Amber

The occurrence of amber in Sierra de Cantabria (Álava, Basque Country) has been known for more than two decades but biological inclusions have only recently been found. The existence of crustaceans (amphipods and isopods), chelicerates (acari and arachnids), 12 orders of insects, and several bird feathers are reported in this preliminary study. In addition, there are leaf remains, molluscs, and a fair number of inorganic inclusions. Pollen analysis of the clastic series indicates an age between upper Aptian-middle Albian, which allows an assignment of this stratigraphic unit to the Nograro Formation. Chemical analysis indicates that the amber has high maturity, which reflects its Cretaceous age. Chemical composition analysis also indicates an araucariacean origin, which is corroborated by pollen found within the amber deposit. This new fossil site provides information for the reconstruction of paleocommunities of arthropods and sedimentary environments in the extreme south of the Basque-Cantabrian Basin during the Lower Cretaceous, characterized by coniferous forests with an understory of vascular cryptograms. Some of the identified arthropods add to the fossil record for various groups that are poorly known or unknown for this time period. This Lagerstätte constitutes one of the most important deposits of Mesozoic amber in the world.

The identification of archaeological amber has been used in Iberian prehistory to evidence long-distance exchanges and engage Iberia in networks that connect western Europe with central and northern Europe, the emergence of social complexity, and the consolidation of trade networks. However, until now, no comprehensive analytical study of the Iberian amber has been produced to support any of the interpretive models currently in use. This paper approaches the analysis of Iberian Peninsula amber artefacts by considering their provenance (based on FTIR characterization), chronology, and spatial relationship with other exotica. Our work increases the number of analyzed artefacts to 156 (24%), out of the c. 647 currently known for the Iberian Peninsula. Based on these new data and a review of Murillo-Barroso and Martinón-Torres (2012), this overview outlines amber consumption patterns from the 6th to 2nd millennia BCE and demonstrates long-distance amber exchange connecting Iberia with the Mediterranean region from the Neolithic period onwards.

We describe a diverse taphocoenosis in a piece of Mexican amber that includes two morphotypes assignable to the leafy liverwort family Lejeuneaceae, an angiosperm seed, a putative bud scale, dematiaceous hyphomycetes as well as dipteran and hymenopteran insects belonging to Phoridae (genera Megaselia, Puliciphora, and Apocephalus), Cecidomyiidae, Psychodidae and Mymaridae (genus Alaptus). Liverworts are known from eight amber deposits but have only rarely been observed in Mexican amber. A perianth-bearing liverwort gametophyte in the piece of amber is classified as Mastigolejeunea extincta sp. nov., and several sterile gametophytes are described as Ceratolejeunea sublaetefusca sp. nov. With these new species, approximately 60 liverworts have been described from amber to date. Remarkable syninclusions include a hyphomycete which is the first darkly-pigmented filamentous microfungus with clear reproductive structures reported from Mexican amber. Fourier Transform Infrared Spectroscopy of a fragment of the investigated amber piece revealed a “Type I” Mexican amber. A whole solubility test suggested a mature resin, although the resin was not much oxidized during the process of amberization. Available evidence suggests that the amber was produced by a Hymenaea tree and that the resin was exposed on its bark, behaving as a sticky trap for insects and vascular plant fragments, and also embedding some epiphytic liverworts and fungi.

Two new species are described from Mexican amber
(15–20 Ma): Cenocephalus tenuis Peris and Solórzano
Kraemer sp. nov. and Tesserocerus simojovelensis Peris and
Solórzano Kraemer sp. nov. Cenocephalus, originally described
as living in Central and South America and then as
fossils from Early to Middle Miocene amber, is noted as morphologically
indistinguishable from Mitosoma, and originally
described as endemic from Madagascar. Thus, we consider
that a close taxonomic relationship exists, even if they are
not the same genus. New evidence of the species already described
in Platypodinae (Tesserocerini) from Mexican and
Dominican ambers (15–20 Ma) and the differences between
those species are discussed, complementing the original descriptions.
The paleobiogeography of Cenocephalus and
Mitosoma is analyzed, which strongly supports the hypothesis
of colonization from Afrotropical Madagascar to America prior
to Early to Middle Miocene (15–20 Ma) via sea currents.
Hymenaea was interpreted as the Mexican and Dominican
resin producers. Based on the analysis of fossil and current
distribution of such plants, our hypothesis considers that the
beetle dispersion occurred with Hymenaea, which was possibly
its host plant.

We present the first known fossilized snake embryo/neonate preserved in early Late Cretaceous (Early Cenomanian) amber from Myanmar, which at the time, was an island arc including terranes from Austral Gondwana. This unique and very tiny snake fossil is an articulated postcranial skeleton, which includes posterior precloacal, cloacal, and caudal vertebrae, and details of squamation and body shape; a second specimen preserves a fragment of shed skin interpreted as a snake. Important details of skeletal ontogeny, including the stage at which snake zygosphene-zygantral joints began to form along with the neural arch lamina, are preserved. The vertebrae show similarities to those of fossil Gondwanan snakes, suggesting a dispersal route of Gondwanan faunas to Laurasia. Finally, the new species is the first Mesozoic snake to be found in a forested environment, indicating greater ecological diversity among early snakes than previously thought.

Provenancing exotic raw materials and reconstructing the nature and routes of exchange is a major concern of prehistoric archaeology. Amber has long been recognised as a key commodity of prehistoric exchange networks in Europe. However, most science-based studies so far have been localised and based on few samples, hence making it difficult to observe broad geographic and chronological trends. This paper concentrates on the nature, distribution and circulation of amber in prehistoric Iberia. We present new standardised FTIR analyses of 22 archaeological and geological samples from a large number of contexts across Iberia, as well as a wide scale review of all the legacy data available. On the basis of a considerable body of data, we can confirm the use of local amber resources in the Northern area of the Iberian Peninsula from the Palaeolithic to the Bronze Age; we push back the arrival of Sicilian amber to at least the 4 th Millennium BC, and we trace the appearance of Baltic amber since the last quarter of the 2 nd Millennium BC, progressively replacing Sicilian simetite. Integrating these data with other bodies of archaeological information, we suggest that the arrival of Baltic amber was part of broader Mediterranean exchange networks, and not necessarily the result of direct trade with the North. From a methodological perspective, thanks to the analyses carried out on both the vitreous core and the weathered surfaces of objects made of Sicilian simetite, we define the characteristic FTIR bands that allow the identification of Sicilian amber even in highly deteriorated archaeological samples.

"The use of amber is documented in the Iberian peninsula since the Palaeolithic. The procurement and trade of this fossil resin has often been considered in discussions of long-distance trade and the emergence
of social complexity, but so far no comprehensive view of the Iberian evidence has been produced to allow a more overarching interpretive model.

This paper presents the Fourier-transform infrared spectroscopy (FTIR) characterization of archaeological amber from three Iberian prehistoric sites: a necklace recovered from the megalithic site of Palacio III (Almadeń de la Plata, Sevilla), a pommel from PP4 Montelirio (Valencina de la Concepción, Sevilla), and a necklace from the Muricecs de Cellers cave (Llimiana, Pallars Jussà, Lleida). Based on these new data and a review of the literature, we present an overview that outlines fluctuations in the use of amber since the Upper Palaeolithic and demonstrates long-distance amber exchange connecting Iberia with northern Europe and the Mediterranean region since the Chalcolithic period at least. We discuss changes in the origins and cultural use of amber and their implications for the consolidation of trade networks."

Amber is of great paleontological importance because it preserves a diverse array of organisms and associated remains from different habitats in and close to the amber-producing forests. Therefore, the discovery of amber inclusions is important not only for tracing the evolutionary history of lineages with otherwise poor fossil records, but also for elucidating the composition, diversity, and ecology of terrestrial paleoecosystems. Here, we report a unique find of African amber with inclusions, from the Cretaceous of Ethiopia. Ancient arthropods belonging to the ants, wasps, thrips, zorapterans, and spiders are the earliest African records of these ecologically important groups and constitute significant discoveries providing insight into the temporal and geographical origins of these lineages. Together with diverse microscopic inclusions, these findings reveal the interactions of plants, fungi and arthropods during an epoch of major change in terrestrial ecosystems, which was caused by the initial radiation of the angiosperms. Because of its age, paleogeographic location and the exceptional preservation of the inclusions, this fossil resin broadens our understanding of the ecology of Cretaceous woodlands.
Proceedings of the National Academy of Sciences04/2010; 107(16):7329-34. · 9.68 Impact Factor

Serrano, M. de L., T.A. Hegna, P. Schaaf, L. Pérez, E. Centeno-Garcia, & F.J. Vega. 2015. The aquatic and semiaquatic biota in Miocene amber from the Campo La Granja Mine (Chiapas, Mexico): Paleoenvironmental implications. Journal of South American Earth Sciences. 62: 243-256.

Amber from the Campo La Granja mine in Chiapas, Mexico, is distinct from other sources of amber in Chiapas. Campo La Granja amber has distinct layers created by successive flows of resin with thin layers of sand on most surfaces. Aquatic and semi-aquatic arthropods are commonly found. Together these pieces of evidence suggest an estuarine environment similar to modern mangrove communities. The aquatic crustaceans are the most intriguing aspect of the biota. A large number of ostracods have been found in the amberdmany with their carapaces open, suggesting that they were alive and submerged in water at the time of entombment. The only known examples of brachyuran crabs preserved in amber are found in the Campo La Granja amber. Amphipods, copepods, isopods, and tanaids are also members of the crustacean fauna preserved in amber.

Tertiary insects and arachnids have been virtually unknown from the vast western Amazonian basin. We report here the discovery of amber from this region containing a diverse fossil arthropod fauna (13 hexapod families and 3 arachnid species) and abundant microfossil inclusions (pollen, spores, algae, and cyanophyceae). This unique fossil assemblage, recovered from middle Miocene deposits of northeastern Peru, greatly increases the known diversity of Cenozoic tropical-equatorial arthropods and microorganisms and provides insights into the biogeography and evolutionary history of modern Neotropical biota. It also strengthens evidence for the presence of more modern, high-diversity tropical rainforest ecosystems during the middle Miocene in western Amazonia.

Amber is a complex, organic polymer that offers unparalleled utility as a preservation medium, providing insights into past organisms and environments. However, under specific circumstances, this information can be compromised through alteration of the amber structure. Understanding the degradation of amber in the geosphere could improve prospecting techniques and maximise the quality and validity of chemical information from altered samples. This study analysed 114 amber samples retrieved from two new Eocene Australian deposits at Strahan, Tasmania and Anglesea, Victoria using a combination of attenuated total reflectance Fourier transform infrared and solid-state 13 C cross-polarised magic angle spinning nuclear magnetic resonance spectroscopy. Results identified both Class Ib polylabdanoid and Class II cadinene-based amber. The presence of Class II amber in Australia suggests one of two possibilities: (1) a local Dipterocarpaceae source, the primary producer of Class II resins, despite the absence of this family from the Australian Eocene fossil record; or (2) a local, unidentified botanical source of cadinene-based amber. A third alternative, that Class II amber was transported to Australia from Southeast Asia via ocean currents, is rejected. Taphonomic analysis revealed four mechanisms of alteration prevalent in amber across the two study regions, with evidence of oxidation and metal carboxylate formation. Both the nature and extent of these alterations were found to vary significantly between classes I and II, suggesting that amber class may play a defining role in determining the chemical pathways by which amber degrades. Of note was the high proportion of amber that exhibited no significant chemical changes despite extensive visible alteration features, suggesting the integrity of palaeobiologi-cal and palaeoenvironmental information in these samples may be preserved.

Fossil records of vertebrate integuments are relatively common in both rocks, as compressions, and amber, as inclusions. The integument remains, mainly the Mesozoic ones, are of great interest due to the panoply of palaeobiological information they can provide. We describe two Spanish Cretaceous amber pieces that are of taphonomic importance, one bearing avian dinosaur feather remains and the other, mammalian hair. The preserved feather remains originated from an avian dinosaur resting in contact with a stalactite-shaped resin emission for the time it took for the fresh resin to harden. The second piece shows three hair strands recorded on a surface of desiccation, with the characteristic scale pattern exceptionally well preserved and the strands aligned together, which can be considered the record of a tuft. These assemblages were recorded through a rare biostratinomic process we call "pull off vestiture" that is different from the typical resin entrapment and embedding of organisms and biological remains, and unique to resins. The peculiarity of this process is supported by actualistic observations using sticky traps in Madagascar. Lastly, we reinterpret some exceptional records from the literature in the light of that process, thus bringing new insight to the taphonomic and palaeoecological understanding of the circumstances of their origins. Amber is fossilised resin originating in ancient forests, with a high capacity for exceptional and three-dimensional preservation of biological remains, providing an outstanding source of information from past ecosystems 1. Arthropods are the most common bioinclusions in amber 2,3 , although vertebrate remains are also often found, including those from Amphibia (e.g., 4) and crown group Reptilia (e.g., 5), such as body fossils and dinosaur feathers (e.g., 6,7). Dinosaur feathers and mammalian hair are keratin integumentary structures which constitute the different forms of vertebrate vestiture 8. The term vestiture is used in this paper for the plumage and pelage of amniotes, thus excluding other dermal structures as scales or glands. Cretaceous amber is an important source of knowledge about feathers, in which they are particularly abundant, providing a panoply of palaeobiological evidence (e.g., 6,7,9,10). Recently, a new study has shown feather-like structures in pterosaurs, so these structures could appear in an archosaur ancestor of dinosaurs and pterosaurs or independently in these two groups 11. Feathers are β-keratin integumentary structures 12 which are present in avian and some non-avian dinosaurs and whose origin has been widely studied 13. The feather structure is composed by medulla, cortex and cuticle (inner to outer) 14. Feathers show high morphological variability, even in the same specimen, so their determination is challenging 14. Mammalian remains are rare in amber, and even more so in amber from the Cretaceous 15,16. A partial mam-malian skeleton which could correspond to a solenodontid was reported from the Miocene amber of the Domini-can Republic 17 , but this is a unique finding since mammals are usually represented in amber by hairs, as in, for example, two records of abundant solenodontid-like hair also found in Dominican amber 18. Hair is an α-keratin integumentary structure occurring since before the emergence of crown mammals 19,20. Like feathers, the hair structure is composed of three layers; medulla, cortex and cuticle, going from innermost to outermost 21-23. The hair cuticle consists of approximately rectangular, flattened, keratin scales composed of an exocuticle rich in sulphur and an endocuticle with low sulphur content 21,23. The overlapping of the keratin scales provides the characteristic surface scale pattern (cuticular pattern) of mammalian hair 22,23. The diverse hair surface scale OPEN