Tuber itzcuinzapotl: A new species of edible Truffle from Mexico.

Truffles, Tuber spp., are Ascomycote Fungi which from ectomycorrhizal relationships with a range of forest Plants, including Pines, Oaks, Hickories, and Orchids. They are distinguished for their large, tuber-like ascomata (fruiting bodies), which are formed underground, which often have highly distinctive aromas and flavours, leading to some species being traded as high-value gourmet items.

There are currently 25 species of Truffle known from Mexico, mostly from the temperate forests of the north and the mountains of the Neovolcanic axis. However, none of these are currently traded as foodstuffs, despite Mexico a globally leading countries in terms of the number of edible wild Fungi consumed, with about 500 species, making it second only China, where about 1000 are consumed. However, recent efforts have found that the non-native Black Truffle, Tuber melanosporum, will form ectomycorrhizal relationships with native Mexican Oaks, and several species found in Mexico are considered to have potential for commercial development, including the Pecan Truffle, Tuber lyonii, which is commercially exploited in the US and Canada, and can trade for up to US$400 per kg.

In a paper published in the journal Phytotaxa on 26 January 2024, Javier Isaac de la Fuente of the Colegio de Postgraduados at Campus Montecillo, Wendy Rosales-Rosales of the Instituto Tecnológico Superior de Zongolica of the Tecnológico Nacional de México, César Romero Martínez-González of the Instituto Tecnológico de Ciudad Victoria of the Tecnológico Nacional de México, Magdelana Martínez-Reyes, also of the Colegio de Postgraduados at Campus Montecillo, Andrea Carolina Elizondo-Salas, also of the Instituto Tecnológico Superior de Zongolica of the Tecnológico Nacional de México, and Jesús Pérez-Moreno, agian of the Colegio de Postgraduados at Campus Montecillo, describe a new species of edible Truffle from the Coniferous mixed forests of eastern Mexico.

The new species is named Tuber itzcuinzapotl, where 'itzcuinzapotl' means 'Dog's Zapote' in the Nahua language (a Zapote is a type of fruit). This Truffle produces subglobose fruiting bodies with a light brown, verrucous-granular outer surface, and an gray or pale brown interior, reaching up to 28 mm by 28 mm in size, with a distinctive fruity taste and smell. It is found growing in association with Mexcan Weeping Pines, Pinus patula, in Veracruz State, Mexico.

Tuber itzcuinzapotl (Holotype). Fresh ascomata fruiting body. De la Fuente et al. (2024).

Mexico has a significant culture of wild Fungus consumption, with over 500 types of Fungi consumed by members of all ethnic groups, and in particular rural communities living close to woodland. However, almost all consumed Fungi are epigeal, i.e, found above the ground, such as Mushrooms, with very little exploitation of subterranean species occurring. This is surprising, as Mexico is one of the most biodiverse regions in the world for Oaks, and Oaks are particularly associated with Fungi producing underground fruiting bodies. 

Tuber itzcuinzapotl is known to be consumed by members of the Nahua ethnic group living in the Sierra de Zongolica region of Veracruz State, Mexico, where it is referred to as 'itzcuinzapotl' (the specific name chosen for the species). Local folklore has it that people began to consume these Fungi after observing Dogs digging them up and eating them. Knowledge of the Fungus appeared to be restricted to older women in the community. Such local knowledge of wild foodstuffs is considered to be at risk in the region as traditional cultures are eroded, leading to loss of knowledge and a reduction and homogenisation in the number of foodstuffs consumed by Humans both in Mexico and globaly.

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Cutting the Gordian Knot of tree-ring timelines in the East Mediterranean Bronze Age, and looking for a date for the Santorini/Thera eruption that destroyed the Minoan civilization.

Tree-ring records constructed from ancient wooden timbers can provide calendar-dated frameworks to underpin archaeological and palaeoenvironmental chronologies beyond the reach of written evidence. They can provide securely dated records of construction, abandonment, and trade across different cultural regions while simultaneously providing calendar-dated, annual resolution records of contemporary climatic variability. As such, they represent an invaluable resource for studies of past human and environmental interactions and for the resolution of complex chronological issues. However, for certain key geographic regions and time periods, the only tree-ring records preserved are not calendar dated to the exact year but rather, 'float' in time, dated with less precision and accuracy by radiocarbon wiggle-match dating (a dating method that uses the non-linear relationship between Carbon¹⁴ age and calendar age to match the shape of a series of closely sequentially spaced Carbon¹⁴ dates with the Carbon¹⁴ calibration curve). While this approach can produce excellent results for certain time periods, limitations of the method include multiyear error ranges and the fact that calibrated date ranges may shift forward or backward in time depending on which iteration of the international radiocarbon calibration curve is used for calibration. The full benefits of the annually derived tree-ring record for establishing rigid archaeological chronologies for cultural interaction plus the impacts of climatic or geological events on ancient civilizations can be fully realized only by securely fixing such records in a precise and accurate calendar-dated range.

In a paper published in the Proceedings of the National Academy of Sciences of the United States of America on 30 March 2020, Charlotte Pearson of the Laboratory of Tree-Ring Research, Geosciences, and the School of Anthropology at the University of Arizona, Matthew Salzer, also of the Laboratory of Tree-Ring Research at the University of Arizona, Lukas Wacker of Ion Beam Physics at Eidgenössische Technische Hochschule Zurich, Peter Brewer, again of the Laboratory of Tree-Ring Research at the University of Arizona, Adam Sookdeo, also of Ion Beam Physics at Eidgenössische Technische Hochschule Zurich, and of the Chronos ¹⁴Carbon-Cycle Facility at the University of New South Wales, and Peter Kuniholm, once again of the Laboratory of Tree-Ring Research, and the School of Anthropology at the University of Arizona, present the results of an attempt to resolve a Bronze Age floating tree-ring record in the Eastern Mediterranean, using using timbers taken from a chamber surrounding the grave of a predecessor of King Midas in the Phrygian capital city of Gordion (modern day Yassihöyük, Turkey).

Map to show the proximity of the Gordion site to Thera, the main direction of fallout of the Thera ash, and other locations. Pearson et al. (2020).

This record is one of a group of interlocking tree-ring series from the ancient East Mediterranean, which when first published as a dated sequence, ncluded wooden timbers from 22 archaeological sites in central Anatolia (Turkey) spanning the years from approximately 2220 to 718 BC. The Gordion part of this sequence was subsequently redated multiple times, with each redate necessitating a reevaluation of the associated archaeological evidence. Aside from being the key to dating a number of critical archaeological sites in the East Mediterranean, the tree-ring series from Gordion has an extra relevance in that it is the only tree-ring record from the ancient Mediterranean that fully spans the period during which all scholars would agree that the Minoan eruption of Thera occurred. This event provides a pivotal marker horizon through which the chronologies of ancient Egypt, the Levant, Greece, and Anatolia could be linked. Dating this tree-ring series to a fixed point in time rather than a shifting calibrated range would, therefore, offer significant new opportunities for dating the eruption and the synchronization point that it offers because it is possible that the tree rings hold an anatomical or chemical marker for the event, which could be used to further refine the dating. This is particularly important as radiocarbon dating for Thera is impeded by a plateau in the radiocarbon calibration curve between about 1620 and 1540 BC.

In particular, if a chemical response related to environmental changes brought about by the eruption could be identified in the wood, as has been observed in both the lake environment at Gölhisar and in the Speleothem record (deposits of secondary minerals that can be dated from their isotope content) in Sofular cave on the Black Sea coast, then it might be possible to suggest a more exact date for the event. While there are many factors that can lead to disturbances in the anatomy of tree rings, there are only a few that can lead to major chemical changes in the environment.

In an earlier attempt to trace the Thera eruption, Pearson et al., published in a paper in the Journal of Archealogical Science in 2009, conducted elemental analysis on a wide growth-ring anomaly from one of the tree-ring site chronologies overlapping with the Gordion record (Porsuk in southern central Turkey). In that study, they found significant changes in elemental chemistry associated with a wide growth-ring anomaly, which was then dated to about 1650 BC; at the time, this was within the possible radiocarbon range suggested for the Thera eruption, at odds with certain lines of archaeological evidence. The elemental response was consistent with what might be expected from a volcanic event but as noted at the time, also consistent with what might be expected following a forest fire. The date for this elemental change and growth response is now outside the possible range for the Thera eruption, although it may originate from some other unidentified eruption; such as the Yali-Nisyros volcano, at the eastern edge of the Aegean volcanic arc. The revised radiocarbon ranges for Thera-relevant materials suggested by Pearson et al. in the earlier study indicate that the majority of the 16th century BC should now be searched for evidence of the eruption.

Left: The 854 anomaly in sample C-TU-POR-3, from Porsuk in southeast Turkey; right: a similar (though extended) growth-ring anomaly from a tree which grew about 30 km from Katmai Volcano, Alaska. The tree in question was inundated with a few feet of pumice following the 1912 AD eruption of Novarupta, attributed to Katmai. The pumice killed or suppressed low vegetation cover, enhancing conditions for established trees. Inset: a short growth anomaly from a single application of fertilizer to a tree in an experimental forest. Pearson et al. (2009).

In the new study, a combination of two approaches was used for improving and securing the date range for the floating tree-ring series from Gordion. First, Pearson et al. compared a sequence of annual Carbon¹⁴ measurements from single rings of the Gordion series with a contemporary time series of annual Carbon¹⁴ from absolute, calendardated Bristlecone Pine, Pinis spp., and Irish Oak, Quercus spp., across the period 1700 to 1500 BC.

Similar applications have relied on detecting the presence of significant rapid excursions in the annual tree-ring Carbon¹⁴, in particular the largest of these discovered so far an approximate 1.2% change between the years 774 and 775 AD. This event has also been used to provide an independent verification of the calendar dating for established multiregional tree-ring records and to synchronize tree-ring Carbon¹⁴ with Berylium¹⁰ (which forms by spallation of nitrogen and oxygen in the atmosphere and precipitates onto and into surface layers) in the ice cores. In the case of the 774/775 AD marker event, the potential is clear, but for time periods where no such dramatic markers are present, like 1700 to 1500 BC, a different strategy has to be applied. Pearson et al. make use of less pronounced and consequently, less secure Carbon¹⁴ time markers for a proposed annual Carbon¹⁴ pattern-matching approach..

Second, this is tested using an anticorrelation between tree growth response to the same volcanic forcing events in both the Mediterranean Juniper, Juniperus spp., trees and calendar-dated North American Bristlecone Pine. This test uses a well-established temporal association between high-elevation Bristlecone Pine frost rings and large-scale volcanic eruptions. It has been clearly demonstrated that latewood frost rings in Bristlecone Pine occur the year of or the year following a volcanic event, and this causal connection has been strongly confirmed across the last 2500 years. Beyond this period, Bristlecone tree-ring chronologies are accurately dated to the calendar year for over 5000 years, and therefore, the record of precisely dated Bristlecone response to volcanism covers the period across which the Juniper sequence lies according to both conventional radiocarbon wiggle matching and the annual Carbon¹⁴ pattern-matching approach used by Pearson et al.

In western Turkey, the years of or following many of the same major volcanic eruptions that affected Bristlecone growth in the more recent period are marked by wide growth rings in Austrian Pine, Pinus nigra. This indicates that an increase in May–June precipitation caused more favorable growth in this region as part of a chain of climatic disturbances associated with Northern Hemisphere cooling following major mid- or northern latitude volcanic eruptions. Assuming that similar climatic forcing prevailed during the Bronze Age and knowing that Pine and Juniper tree-ring chronologies from this region show strong interspecies correlation, Pearson et ai. hypothesised that wide rings in the floating Juniper sequence should correlate with calendar-dated frost events in Bristlecone Pine and that, if so, this could provide a means to test the annual Carbon¹⁴-matching approach and to refine to a fixed tree-ring date based on synchronization with the calendar-dated Bristlecone record (in a similar approach to previous studies that used Bristlecone Pine frost rings as fixed date volcanic markers to refine dating for volcanic acidity layers in ice cores).

Finally, Pearson et al. report the chemical study of this newly secured tree-ring sequence with the objective of seeing if any chemical indicator could be found that might help to further constrain the dating possibilities for the Thera eruption.

Annual Carbon¹⁴ measurements were made on 186 consecutive years (relative years 834 to 1019) of the 1028-year Gordion Juniper sequence (which starts with relative year 737). These measurements into the IntCal13 Radiocarbon Age Calibration Curve using the OxCal 4.3 radiocarbon calibration program to provide an end date for the entire calibrated tree-ring chronology, within an 8-year range: 758 to 751 BC at 95.4% confidence level. This was in good agreement with previous wiggle matching of 128 decadal or 11-year blocks spaced over 987 years of the same Juniper sequence, which placed the end of the tree-ring sequence at 751 BC +6/–8 at a 95.4% confidence level. A chi-squared (χ²) test (used to determine whether there is a statistically significant difference that is unlikely to be due to chance alone between expected frequencies and observed frequencies) for the Mediterranean Carbon¹⁴ time series vs. the weighted mean of the annually resolved combined Oak and Pine data placed the last ring of the Mediterranean sequence at a more precise date of 745 ± 4 BC (95.4% confidence level); this is statistically slightly younger (10 ± 6 years) than when the same data are wiggle matched to IntCal13. Pearson et al. considered the position using the annual Carbon¹⁴ data as significantly more reliable as it is a result of comparing fine structure that is not available in IntCal13, which is primarily based on decadal data. Using the fine structure yields dating results free from the regional or laboratory offsets that may be combined in the coarser-resolution calibration data. The reasonably close agreement of the results via the different methods does, however, demonstrate that, for wiggle matches spanning multiple decades, the improved curve shape offered by the annual Carbon¹⁴ data may have a relatively small effect on the final calibrated date range.

Positioned relative to an end date of 745 ± 4 BC the visual correlation of the annual data around the increased production event of circa 1528 BC is clearly evident. The Gordion data more closely agree with the annual Oak and Pine data than with IntCal13 and show the same offset from the curve as shown by the other annual data between 1650 and 1540 BC. They are also valuable in providing an annually based record of Carbon¹⁴ fluctuation from the Mediterranean region in this time period relevant for the Thera eruption. While no large-scale localized offsets in Carbon¹⁴ are evident, for the years where contemporary Oak, Pine, and Juniper measurements from the same laboratory can be directly compared (1680 to 1580 BC), the Mediterranean Juniper is offset from the Irish oak by +9.0 ± 3.5 Carbon¹⁴ years, whereas they are only +3.4 ± 2 Carbon¹⁴ years different from the North American Pine. While this slight difference is within the stated measurement errors, it is possible that the closer agreement between the Pine and Juniper may reflect a shared, more southerly latitude than the Irish Oak. These data agree with previous findings that there is no major regional offset in the period. Pearson et al. also note that the data indicate that, around the period of lower solar activity (around 1600 BC) and during the period of more rapid Carbon¹⁴ production (roughly 1540 to 1528 BC), there is no significant difference between the multiregional annual Carbon¹⁴ data, which might be related to growth season. Pearson et al. do, however, note the possibility of a localized excursion in Carbon¹⁴ around 1548 BC. This requires further investigation as, if it is not an analytical outlier, it could represent an influx of  'old carbon' into the environment, potentially consistent with a volcanic eruption such as Thera.

The validity of the dated position produced by chi squared analysis (745 ± 4 BC at a 95.4% confidence level) and supported by annual Carbon¹⁴ pattern matching around the 1528 BC Carbon¹⁴ excursion was then independently tested using the previously described correlation between years of known eruptions, calendar-dated Bristlecone Pine frost-ring years, and wide tree rings in Mediterranean sequences. Pearson et al. hypothesised that, if their temporal placement of the Juniper chronology was correct at 745 ± 4 BC, then it should show wide rings in the year of or following a Bristlecone Pine frost ring. On this basis, superposed epoch analysis (a statistical tool used in data analysis either to detect periodicities within a time sequence or to reveal a correlation, usually in time, between two data sequences) was used to test the significance of the effects of a mean tree-ring response to the proxy record of volcanic forcing across the full Bronze–Iron Age Juniper chronology in the adjusted position suggested by this study. In this position, the superposed epoch analysis analysis showed significantly wider rings than would be expected by chance in the Mediterranean chronology in the year following a Bristlecone frost ring. This nonrandom association provides strong corroborative evidence for the annual Carbon¹⁴ position to, in fact, be correct to the year. Within the 4 years on either side of the 745 BC dating placement, no other positions provide this strong association. This provided additional support that the position of the Gordion chronology determined by the chi-squared analysis is indeed correct to within 1 year and allowed Perason et al. to derive an exact calendar-dated position for the tree-ring series.

Having arrived at a secure date range for the tree-ring series, Pearson et al. made multiple scans using a desktop ATLAS Micro-X-ray Fluorescence unit across the transverse surface of a subsample of GOR-76. The scans covered the period from circa 1630 to 1500 BC. These revealed a single major disturbance of the element Calcium around 1560 BC. The exact onset of the change may be as early as 1562/1 BC, and the effect appears to last until around 1557 BC. Other analytical techniques will be used to refine this temporal association. Calcium is an essential element in wood that is needed to support fundamental biological functions, including cell membrane stability and stress response. Declines in tree-ring Calcium have previously been associated with drought; however, in this case, the growth rings that feature the depletion are not unusually narrow (as would indicate drought). A forest fire response is also a possible explanation, and this can manifest as either an increase of Calcium as it becomes more available for uptake after burning or as a depletion where areas of the sample are scarred but again, the tree-ring growth pattern does not indicate a growth release or scar typical of fire impact.

A high-resolution X-ray fluorescence scan of the transverse section of GOR-76 featuring an unusual depletion of the element Calcium. The mapped area was identified as the only significant elemental anomaly in the 16th century BC growth rings from this sample. This scan shows that a calcium depletion occurs from around 1562 to 1558 BC and is centered on an unusually wide, slightly pale in colour growth ring at 1560 BC. A similar wide, pale ring occurs in 1550 BC but does not indicate the same degree of depletion. Pearson et al. (2020).

Alternatively, Calcium can be reduced in tree rings following foliar exposure to acid mist or other such precipitation. Therefore, the finding of a Calcium depletion is consistent with the impact of volcanically induced acid deposition [reported in lake sediments as a result of the Thera eruption. On its own, this Calcium response in a single tree might not be worth reporting; however, the date around which it occurs makes it worthy of further discussion because 1560 BC also coincides with evidence for volcanic impact indicated in two other records. Subfossil Pine trees from a calendar-dated record in Finnish Lapland indicate a possible eruption immediately preceding 1560 BC in the form of a negative departure in Carbon¹³ (drop in the proportion of Carbon¹³ relative to Carbon¹²), which has been shown to correlate with periods of reduced visibility due to volcanic acid fog. The high-altitude Bristlecone pine record also includes an indicator year at 1560 BC along with 4 other years in the 16th century BC when unusually narrow growth or frost-damaged cells are recorded. These dates (1597, 1560, 1546, 1544, and 1524 BC) are all indicative of major volcanic eruptions, the origins of which are not yet known. The coincidence of these two additional records around 1560 BC makes further investigation essential. The apparent increase in old carbon around 1558 BC also requires further exploration as, although the tree grew several 100 km from the eruption, this too could hypothetically connect with the Thera eruption, and all potential indicators should be explored. We note, however, that 1560 BC is more recent than indicated likely for the chemical change associated with the Thera eruption at Sofular cave and older than is indicated likely for the event via certain lines of archaeological evidence Nevertheless, these findings clearly merit further careful investigation to define better the onset and duration of the response and to see if it can be replicated in other trees and expanded via the detection of other more clearly volcanogenic (or otherwise) elemental markers.

Pearson et al.'s study shows that, even in the absence of a large-scale interannual Carbon¹⁴ excursion (such as at 774/775 AD), comparing the fine structure in annually derived Carbon¹⁴ time series via a range of approaches can offer a way to improve the dating precision and accuracy possible for floating tree-ring sequences previously dated by conventional radiocarbon wiggle matching to the IntCal calibration curve. First, critically, matching based on two annual Carbon¹⁴ time series (one of which is calendar dated via dendrochronology) offers a dated position for the floating sequence, which is fixed. This differs from modeled dates via conventional radiocarbon wiggle matching, which may change with new iterations of the calibration curve. Second, chi-squared testing of longer annually based time series can refine dating for floating tree-ring sequences to a precise year within a ± 4-year range, and this can be visually tested and confirmed across small-scale Carbon¹⁴ features (such as at 1528 BC). Third, as is the case in this study, additional proxy information can be used to refine the dating further. We found that other tree-ring associations strongly suggested that the dating indicated by the annual Carbon¹⁴-matching approach yielded a result that was in fact accurate to within 1 year. This combination of methods opens up opportunities to anchor floating tree-ring sequences in time outside the capacity of standard dendrochronological techniques, demonstrating potential to fill in a range of critical temporal and geographic gaps in the tree-ring record.

Anchoring the Gordion tree-ring series more securely in time is an important contribution to improving timelines in the ancient East Mediterranean and maximizing the potential of this record as a paleoenvironmental resource. The first step toward this is the identification of the calcium anomaly around 1560 BC, which while clearly requiring replication and much further substantiation, opens up potential that may now be pursued toward finding an exact date for Thera.

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Wildfires cause at least one fatality in Lebanon.

One person died and about seventy more required hospital treatment as a series of forest fires swept across Lebanon on Monday 14-Tuesday 15 October 2019. The fires broke out in Pine forests in many parts of the country, fuelled by a combination of unusually high temperatures (in excess of 40°C in places) and strong winds, overwhelming local emergencies in many areas, and forcing people to flee their homes. Most of the fires were eventually brought under control on Wednesday 16 October, by a combination of rainfall and fire-fighting aircraft from Jordan, Cyprus, and Greece, arriving to support Lebanon's own two such planes. Fires are also known to have broken out in neighbouring parts of Syria, though it is unclear how they have been dealt with in the war-torn country.

A fire burning near the village of Meshref in the Shouf Mountains to the south of Beirut. AFP.

Wildfires can be particularly dangerous in areas with extensive Pine forests, as many Pine species are fire adapted, having evolved in a number of ways that help them cope with frequent fires. Such trees have thick, fire resistant bark, which protects the vascular tissues of the trunk (cambium) from heat damage; a 15 mm thick bark layer can protect the interior of the tree against external temperatures as high as 400°C for as long as 3 minutes (generally long enough for any available fuel to be consumed at these temperatures). Pines also produce a large number of long, flammable needles, which drop to the ground around the trees, causing any fires to burn rapidly and intensely, i.e. in a way that the Pine can cope with, but any competitor Plants nearby might find challenging. In some Pine species these needles are retained on the branches, resulting in an intense fire in the canopy, something which again is likely to prove challenging to competitors. In such trees the Pine seeds are typically also retained in cones within the canopy, with the cones only opening and shedding the seeds after being exposed to fire, presenting the new seeds with soil enriched by the forest fire and cleared of competitors.

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Thousands forces to flee their homes as wildfire sweeps across central Gran Canaria.

Around 9000 people have been forced to flee their homes as a wildfire sweeps across the northwest part of central Gran Canaria this week. The fire started near the town of Tejeda on Saturday 17 July 2019, and has so far proved impossible to bring under control. The fire has destroyed about sixty square kilometres of land cover in a mountainous region largely covered by wooded ravines, much of it in the ancient Pine forests of the Tamadaba Natural Park. There are no reports of any injuries at this time, but it is thought that several hundred homes have been destroyed.

Fire burning near El Rincón on Gran Canaria on 18 August 2019. Cabildo de Gran Canaria/AP.

The cause of the fire has not yet been determined, though local authorities have not yet ruled out the possibility that it may have been deliberately set, but it has spread rapidly due to a combination of exceptionally high temperatures in the area (over 40°C), combined with low humidity and high winds. Flames in excess of 50 m high have been reported, which helps the fire jump to new places. Pine forests are particularly prone to fires, as Pines produce a large number of long, flammable needles, which drop to the ground around the trees, causing any fires to burn rapidly and intensely.

Fire fighters trying to tackle a wildfire on Gran Canaria this week. AP.

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Tobleria bicuspis: The earliest cone-producing Conifer?

Modern Conifers bear their seeds in cones, structure in which the seeds are attached to scales arranged spirally on a central bract. A similar situation is seen in Conifers from Mesozoic and Cainozoic deposits, but the earliest, Carboniferous Conifers, placed in a group called the Voltziales, are somewhat different, with seeds found in the axils of fertile leaf shoots (the angle between the base of the leaf shoot and the stem), which are arranged in a loosely radial pattern on a stem. The first seed cones appear in the Voltziales towards the end of the Early Permian.

In a paper published in the journal PhytoKeys on 25 March 2019, Isabel Van Waveren of the Naturalis Biodiversity Center discusses the peasence of cones in Tobleria bicuspis, a Voltziales Conifer from the Earliest Permian Jambi Palaeoflora of Jambi Province in Sumatra, Indonesia.

The Jambi Palaeoflora comprises a number of coalified plant fossils excavated from outcrops of the Mengkarang Formation along tributaries of the Merangin River. These deposits are thought to be between 296.77 and 296.14 million years old, and were laid down in a tropical forest about 15° north of the Equator. Eighteen samples were used in the study, seventeen of which were collected in 1925 by Wilhelmus Jongmans and Walther Gothan, plus one specimen collected from the same area in 2006.

Map of the Bangko area showing the outcrops of the Mengkarang Formation along the distributaries of the Merangin River where Tobleria bicuspis was found. Van Waveren (2019).

Examination of the samples found that they had cones made up of tightly packed bicuspid (double tipped) scales (typical for cone-bearing members of the Voltziales). The most intact of these (from sample 45311, a slab of light beige, finely banded, tuffaceous mud collected along the Karing River by Jongmans and Gothan) is 24 mm long, and 8-9 mm wide at the base, tapering to about 4-5 mm, although this is not a complete cone, with the base being broken so that it would have originally been somewhat longer.

The three cones from sample 45311: (A) cone C1, (B) Tobleria bicuspis right edge of cone C2 fragment showing bicuspid scale and seeds (C) Tobleria bicuspis cone C3 fragment showing bicuspid scale. Arrows 1–4 in Figure (A) indicate scales in side view, arrow 5 indicates the cone axis. The arrow in Figure (C) indicates a bifid scale. Scale bars: 10 mm (A); 2,5 mm (B); 5 mm (C). Van Waveren (2019).

Each of the scales is about 3 mm wide and 5 mm long, and has two, linked 'fertile utits' (seeds) on its inner surface. These 'fertile units' vary somewhat in shape, from adpressed hemispheres, to heart-shapes attached at the central and narrowest points, to paired almond shapes. These vary in length between 0.6 and 2.6 mm, and in width between 0.4 and 1.6 mm.

Details of dispersed seeds, scales and fertile scales: (A) paired seeds with double wall (sample 45311C) (B) paired seeds with triangular micropylar protrusion (sample 45311 E) (C) detail of triangular micropylar protrusion from paired seeds (sample 45311 E) (D) heart shaped paired seeds/ovules (sample 45311 D) (E) heart shaped paired seeds/ovules (sample 45311 B) (F) juxtaposed almond shaped seeds/ovules (sample 45311 B) (G) bicuspid scale (sample 45311 Aa) (H) bicuspid scale (sample 45311D) (I) bicuspid scale (sample 45471) (J) bicuspid scale with contour of two seeds/ovules (sample 45315) (K) bicuspid scale with darker organic contour of seed (sample 45310) (L) bicuspid scale with heart shaped contour of seeds/ovules (sample 45471). Van Waveren (2019).

Van Waveren notes that four Conifer groups were producing cones by the end of the Permian, the Cordaitanthales, the Ferugliocladales, the Dicranophyllales, and the Voltziales, as well as three non-Conifer groups, the Cycadalean, the Gnetaleans, and the Peltaspermaleans. The first Cycad cones appear in the Early Permian, but are quite distinct from Conifer cones, with their seeds located laterally to (sideways of) their cones, the earliest known Gnetalean cones appear in the Late Permian of China, and are spear-shapes, with single seeds, and the Peltaspermaleans have very rounded scales. The scales and seeds of the Cordaitanthaleans form a distinct wing shape, while the seeds of the Ferugliocladales are attached to the cone axis rather than the scales, while the scales of the Cheirolepidiales are triple in form, but encase a single seed. The cone-bearing Voltziales, in contrast typically have bicuspid cone-scales and double seeds, leading Van Waveren to conclude that the placement of Tobleria bicuspis in this group is quite safe taxonomicaly.

Reconstruction of Tobleria bicuspis. Scale bar is 1 cm. Van Waveren (2019).

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Understanding the extraordinary success of Pines.

Gymnosperms (Non-flowering Seed Plants) first arose in the Devonian, and by the Mesozoic had come to dominate almost all terrestrial ecosystems. Angiosperms appeared some time in the Jurassic or Early Cretaceous, and appear to have initially been minor components of the terrestrial flora, but began to rapidly diversify in the Middle Cretaceous, and by the end of that period had become the dominant group of Plants on Earth, leading to the extinction of formerly successful groups such as the Bennettitales and Seed Ferns, while other groups, such as the Gingkoes, Cycads, and Tree Ferns underwent huge declines, and only survive as relict groups with a few remotely scattered populations today. One Gymnosperm group, however, has done remarkably well in an Angiosperm-dominated world. The Conifers, and in particular the Pines, Pinus spp., underwent a significant diversification at the same time as the Angiosperms, and apparently thrived in the environment that these Plants created. Pines have continued to be a success story in the post-Cretaceous world, and have undergone a series of extra expansions as terrestrial ecosystems became dominated by first Grasses and then Humans.

In a paper published in the journal Ecology and Evolution on 21 September 2018, Surendra Singh of the Central Himalayan Environment Association, Inderjit of the Centre for Environmental Management of Degraded Ecosystems at the University of Delhi, Jamuna Singh of the Department of Botany at Banaras Hindu University, Sudipto Majumdar, also of the Centre for Environmental Management of Degraded Ecosystems, Jaime Moyano and Martin Nuñez of the Grupo de Ecologia de Invasiones at the Universidad Nacional del Comahue, and David Richardson of the Centre for Invasion Biology at Stellenbosch University, examine the reasons for the extraordinary rise of the Pines, and their continued success in modern, Human-dominated landscapes.

Pines in the Northern (native) and Southern (nonnative) Hemispheres. (a) Pinus longaeva in the White Mountains, California, USA; (b) Pinus contorta, southern California, USA; (c) Pinus halepensis, southern France; (d) Pinus pinaster, Andalucía, Spain; (e) Pinus contorta, colonising subalpine meadow, Sequoia National Forest, California, USA; (f) Pinus roxburghii in the Himalaya, Uttarakhand, India; (g) Pinus contorta invading Patagonian steppe vegetation, near Bariloche, Argentina; (h) Pinus pinaster invading fynbos shrubland, Western Cape, South Africa. David Richardson and Inderjit in Singh et al. (2018). 

The rise in Angiosperms during the Cretaceous was associated with a changed fire regime; put simply forests of Angiosperm trees were able to survive frequent forest fires while most Gymnosperms were not, so that any Gymnosperm living in an Angiosperm-dominated woodland had a good chance of being killed by each fire cycle, while the Angiosperms surviving it simply grew back. Pines, however, did not suffer this problem, with the genus splitting into two subgenera with different strategies for surviving fire early in the group’s history.

Members of the subgenus Diploxylon, sometimes known as ‘Hard Pines’, are fire adapted, having evolved in a number of ways that help them cope with frequent fires. Firstly these trees have thick, fire resistant bark, which protects the vascular tissues of the trunk (cambium) from heat damage; a 15 mm thick bark layer can protect the interior of the tree against external temperatures as high as 400°C for as long as 3 minutes (generally long enough for any available fuel to be consumed at these temperatures). Secondly these Pines produce a large number of long, flammable needles, which drop to the ground around the trees, causing any fires to burn rapidly and intensely, i.e. in a way that the Pine can cope with, but any competitor Plants nearby might find challenging. In some Pine species these needles are retained on the branches, resulting in an intense fire in the canopy, something which again is likely to prove challenging to competitors. In such trees the Pine seeds are typically also retained in cones within the canopy, with the cones only opening and shedding the seeds after being exposed to fire, presenting the new seeds with soil enriched by the forest fire and cleared of competitors.

Pines of the subgenus Haploxylon (or Strobus), sometimes known as ‘Soft Pines’, in contrast, survived the evolution of new fire regimes in the Cretaceous by simply avoiding Angiosperm forests completely, evolving traits that enabled them to survive in areas such where Angiosperms could not. These Pines also have thick bark, though in this instance it is used as an insulator against the cold, with such trees able to survive temperatures as low as -90°C, and have closable stomata which enable them to survive in very dry conditions. These Pines developed an ectomycorrhizal relationship (relationship in which the root is surrounded by a sheath of Fungi) with Basidiomycete Fungi by the Middle Eocene, giving them an additional advantage in colonising cooler northerly and high altitude environments, as these Fungi are more tolerant of such conditions than the arbuscular mycorrhizal relationship (relationship in which Fungal fibres penetrate the root) most other Plants form with Ascomycete Fungi; to date only one group of Angiosperms have formed a similar relationship with the Basidiomycetes, the Fagales (Beeches, Oaks etc.).

These adaptations have enabled Pines to survive a number of new conditions that have arisen in the post-Cretaceous world, such as the evolution of savanna ecosystems, grasslands with an annual fire cycle, impossible to colonise for trees without adaptations to fires, or the Pleistocene glaciations, during which cold-adapted Pines were able to survive in refugia unavailable to less hardy Plants, giving them a considerable advantage when the glaciers cleared, opening up large areas for colonisation by the surviving tree species.

The appearance of Humans has created a number of new opportunities for Pines, firstly through the spread of slash-and-burn agriculture, which sweeps away other tree species, creating opportunities for fire-adapted Pines, and then by the active planting of Pines for their long, straight trunks and excellent timber. Humans have carried Pines to many new environments, particularly in the Southern Hemisphere, where they have often become highly invasive in ecosystems unused to them. Pines have been able to invade a number of Southern Hemisphere ecosystems that were formerly treeless, such as the arid Patagonian steppe, South African fynbos, and the grasslands and shrublands of New Zealand, where dry conditions and periodic fires had excluded native tree species. The ability of Pines to survive at high altitudes has also given them a novel advantage in the Southern Hemisphere, where no other trees are adapted to do this, for example in the native treeline is found at 1950 m above sea level in Chile, and in New Zealand it is even lower at 1350 m, but in both areas Pines can climb as high as 4000 m above sea level, giving them the opportunity to colonise large areas of mountainside formerly free of trees.

Key drivers and responses during the evolution of pines. Gymnosperms originated in the Devonian (350 Myr ago), but Pines originated ~150 Myr ago. Oval shapes indicate environmental filters, red ovals for Diploxylon and blue ovals for Haploxylon Pines. The presence of different groups is represented by numbers: (1) Gymnosperms; (2) Pines prior to diversification; (3) Diploxylon; (4) Haploxylon; (5) Angiosperms; (6) C3 Grasses; (7) C4 Grasses. Solid red ovals indicate fire as a driver, and solid blue ovals denote extreme environments as drivers. Dashed red or blue ovals indicate the impact of humans. Angiosperms, mainly shrubs and herbs, appeared as understorey ruderals in the Late Cretaceous (65–145 Myr ago) and later proliferated in response to novel fire regimes. This resulted in the shift of community structure as slow-growing Gymnosperms were replaced by fast-growing Angiosperms, resulting in the decline of Gymnosperms except Conifers. Changes in the climate in the Miocene (5–24 Myr ago) led to the replacement of woodlands with grasslands dominated by C4 species. Highly flammable C4 grasses became abundant in open areas with higher light availability. Pinus has shown remarkable adaptability to highly flammable ecosystems, including frequently burned C4 grasslands. The timing of Angiosperm evolution overlaps with the origin and diversification of pines into Diploxylon and Haploxylon taxa. Haploxylon taxa are fire-avoiding and occur in drier and colder regions, whereas Diploxylon taxa are fire-adapted and occur in more productive environments at subtropical and temperate latitudes. Diploxylon Pines evolved to adapt to fire and codominate with Angiosperms in some more productive regions outside tropical rain forests. Singh et al. (2018). 

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Oligopipiza quadriguttata: A new species of Pipizine Hoverfly from the Middle Oligocene of France.

Hoverflies, Syrphidae, are one of the most successful groups of True Flies, Diptera, alive today, found on all landmasses except Antarctica, Spitzbergen and some remote oceanic islands. They play a significant ecological role, both as adult pollinators and as voracious predators during their larval stages, and are thought to have appeared during the Middle Cretaceous, around the time when Angiosperms (Flowering Plants) were rapidly diversifying and coming to dominate most terrestrial ecosystems. Despite this success, the fossil record of Hoverflies is rather sparse, with only 106 fossil species described, the most recent of which was identified in 2005.

In a paper published in the journal Acta Palaeontologica Polonica on 20 July 2018, Valentin Nidergas of the Institut Systématique Evolution Biodiversité at the Muséum national d’Histoire naturelle, Jiří Hadrava of the Department of Zoology at Charles University, Romain Garrouste, also of the Institut Systématique Evolution Biodiversité at the Muséum national d’Histoire naturelle, Jakub Prokop, also of the Department of Zoology at Charles University, and Thomas Schubnel and André Nel, again of the Institut Systématique Evolution Biodiversité at the Muséum national d’Histoire naturelle, describe a new species of Hoverfly from the Middle Oligocene clay-limestone laminites of the National Geological Reserve of Lubéron at Cereste in France.

The new species is named Oligopipiza quadriguttata, where ‘Oligopipiza’ derives from ‘Oligocene’ and ‘Pipiza’ a modern genus which the new Hoverfly resembles, and ‘quadriguttata’ means ‘four drops’ in reference to the markings on the abdomen of this species. Oligopipiza quadriguttata is named from four male and four female specimens, obtained by splitting the laminites with a hammer and a spatula. These specimens are 6.8-8.1 mm in length, with hairy abdomens, thoraxes and legs, with two pairs of yellow, drop-shaped markings on the abdomens; these vary in size but are always present. 

Pipizine hoverfly Oligopipiza quadriguttata, male. Rupelian, Céreste, France. Nidergas et al. (2018).

Many of the specimens assigned to the species were covered in what appeared to be Pine pollen. This is surprising, as while modern Hoverfly’s are significant pollinators, no there are no recorded instances of modern Pines being pollinated by Hoverflies, or indeed any other Insect, the group being entirely wind-pollinated today. However, the Lubéron deposits are thought to have been laid down in a mixed Pine/broadleaf forest, a similar habitat to that occupied by many European Pipizine Hoverflies today, with macrofossils of Pine fragments being quite common, but no previously recorded Pine pollen. This is curious, as (wind-pollinated) Pines usually produce copious amounts of pollen, which is likely to be preserved in any local deposits preserving other fossils. The presence of a Pine species reliant on Insect pollination might help to explain this, as such as species could produce far less pollen, and would not need to shed it so freely into the environment.

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