[Paleontology • 2022] A 2-Million-year-old Ecosystem in Greenland uncovered by environmental DNA

the rich plant and animal assemblages of the Kap København Formation in North Greenland.

in Kjær, Pedersen, Sanctis, Cahsan, Korneliussen, ... et Willerslev, 2022. 

DOI: 10.1038/s41586-022-05453-y

 — image: Beth Zaiken/bethzaiken.com

 twitter.com/BZaiken

Abstract

Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago had climates resembling those forecasted under future warming. Palaeoclimatic records show strong polar amplification with mean annual temperatures of 11–19 °C above contemporary values. The biological communities inhabiting the Arctic during this time remain poorly known because fossils are rare5. Here we report an ancient environmental DNA6 (eDNA) record describing the rich plant and animal assemblages of the Kap København Formation in North Greenland, dated to around two million years ago. The record shows an open boreal forest ecosystem with mixed vegetation of poplar, birch and thuja trees, as well as a variety of Arctic and boreal shrubs and herbs, many of which had not previously been detected at the site from macrofossil and pollen records. The DNA record confirms the presence of hare and mitochondrial DNA from animals including mastodons, reindeer, rodents and geese, all ancestral to their present-day and late Pleistocene relatives. The presence of marine species including horseshoe crab and green algae support a warmer climate than today. The reconstructed ecosystem has no modern analogue. The survival of such ancient eDNA probably relates to its binding to mineral surfaces. Our findings open new areas of genetic research, demonstrating that it is possible to track the ecology and evolution of biological communities from two million years ago using ancient eDNA.

Kurt H. Kjær, Mikkel Winther Pedersen, Bianca De Sanctis, Binia De Cahsan, Thorfinn S. Korneliussen, Christian S. Michelsen, Karina K. Sand, Stanislav Jelavić, Anthony H. Ruter, Astrid M. A. Schmidt, Kristian K. Kjeldsen, Alexey S. Tesakov, Ian Snowball, John C. Gosse, Inger G. Alsos, Yucheng Wang, Christoph Dockter, Magnus Rasmussen, Morten E. Jørgensen, Birgitte Skadhauge, Ana Prohaska, Jeppe Å. Kristensen, Morten Bjerager, Morten E. Allentoft, Eric Coissac, PhyloNorway Consortium, Alexandra Rouillard, Alexandra Simakova, Antonio Fernandez-Guerra, Chris Bowler, Marc Macias-Fauria, Lasse Vinner, John J. Welch, Alan J. Hidy, Martin Sikora, Matthew J. Collins, Richard Durbin, Nicolaj K. Larsen and Eske Willerslev. 2022. A 2-Million-year-old Ecosystem in Greenland uncovered by environmental DNA. Nature. 612; 283–291. DOI: 10.1038/s41586-022-05453-y

 twitter.com/BZaiken/status/1600561081050861569

 https://phys.org/news/2022-12-discovery-world-oldest-dna-million.html

 

 

The lost world: The cover shows an artist’s impression of the rich ecosystem that existed in parts of northern Greenland some 2 million years ago. The ecosystem is reconstructed from ancient DNA in this week’s issue by Eske Willerslev and colleagues. Working at the Kap København Formation in Peary Land, the researchers gathered sediment samples rich in organic material from 5 different geological sites. By extracting and sequencing DNA from these samples, they were able to piece together a picture of the flora and fauna present around 2 million years ago. The team found evidence of open boreal forest mixed with Arctic species such as cedar, spruce and birch, as well as signs of animals including hares, mastodons, reindeer and geese. The evidence affirms that this part of Greenland, now a polar desert, was 11–17 °C warmer than it is today and suggests it was home to an ecosystem composition that no longer exists anywhere in the world.

 — Cover image: Beth Zaiken/bethzaiken.com twitter.com/BZaiken

[Paleontology • 2022] Cretaceous Dinosaurs across Alaska Show the Role of Paleoclimate in Structuring Ancient Large-Herbivore Populations

Examples of vertebrate fossil data used in this study.
(1) Prince Creek Formation, North Slope, C1, bonebed.
(2) lower Cantwell Formation, Denali National Park, C2, ceratopsian footprint.
(3) Chignik Formation, Aniakchak National Monument, C3 hadrosaur footprint.

in Fiorillo, McCarthy, Kobayashi & Suarez, 2022.

DOI: 10.3390/geosciences12040161 

 twitter.com/dgdt2425 

Abstract

The partially correlative Alaskan dinosaur-bearing Prince Creek Formation (PCF), North Slope, lower Cantwell Formation (LCF), Denali National Park, and Chignik Formation (CF), Aniakchak National Monument, form an N–S transect that, together, provides an unparalleled opportunity to examine an ancient high-latitude terrestrial ecosystem. The PCF, 75–85° N paleolatitude, had a Mean Annual Temperature (MAT) of ~5–7 °C and a Mean Annual Precipitation (MAP) of ~1250 mm/year. The LCF, ~71° N paleolatitude, had a MAT of ~7.4 °C and MAP of ~661 mm/year. The CF, ~57° N paleolatitude, had a MAT of ~13 °C and MAP of ~1090 mm/year. The relative abundances of the large-bodied herbivorous dinosaurs, hadrosaurids and ceratopsids, vary along this transect, suggesting that these climatic differences (temperature and precipitation) played a role in the ecology of these large-bodied herbivores of the ancient north. MAP played a more direct role in their distribution than MAT, and the seasonal temperature range may have played a secondary role.

Keywords: hadrosaurs; ceratopsians; Arctic; ancient Arctic; terrestrial ecosystems; ecosystem reconstruction

Figure 1. Maps showing general locations of study areas. (A) Modern Alaska. (B) Polar projection of tectonic plates during the Late Cretaceous (Base map from PLATES Project, University of Texas Institute of Geophysics). The inner latitudinal ring on map represents 45° N.
 (C) Examples of vertebrate fossil data used in this study. (1) Prince Creek Formation, North Slope, C1, bonebed. (2) lower Cantwell Formation, Denali National Park, C2, ceratopsian footprint, Denali National Park. (3) Chignik Formation, Aniakchak National Monument, C3 hadrosaur footprint.

Examples of vertebrate fossil data used in this study. (1) Prince Creek Formation, North Slope, C1, bonebed. (2) lower Cantwell Formation, Denali National Park, C2, ceratopsian footprint, Denali National Park. (3) Chignik Formation, Aniakchak National Monument, C3 hadrosaur footprint.

 

   

 Anthony R. Fiorillo, Paul J. McCarthy, Yoshitsugu Kobayashi and Marina B. Suarez. 2022. Cretaceous Dinosaurs across Alaska Show the Role of Paleoclimate in Structuring Ancient Large-Herbivore Populations. Geosciences. 12(4)  (Special Issue: Terrestrial Paleoclimatology and Paleohydrology of the Cretaceous Greenhouse World); 161. DOI: 10.3390/geosciences12040161

  twitter.com/dgdt2425/status/1519512980265652224

Cover Story: The impacts of a changing climate are of major societal concern with great interest on mitigation or modeling how a future, warmer world would look. It is also broadly recognized that the impacts of a warming Earth are most profoundly expressed in the polar regions. Climate change encompasses many components. Our new study reviews the ample evidence for a flourishing ancient Arctic terrestrial ecosystem during the Late Cretaceous greenhouse mode in Earth history, an ecosystem where the local paleoclimate was a primary driver in structuring the relative abundances of large-bodied herbivores in local environments. Further, analysis suggests that mean annual precipitation (MAP) played a more direct role in determining the distribution of herbivorous dinosaurs than mean annual temperature (MAT) did. 

[PaleoMammalogy • 2022] Concealed Weapons: A Revised Reconstruction of the Facial Anatomy and Life Appearance of the Sabre-toothed Cat Homotherium latidens (Felidae, Machairodontinae)

Reconstruction of Homotherium latidens based on the fossil specimen MNHN.F.PET 2000 a & b from Perrier

in Antón, Siliceo, Pastor & Salesa, 2022. 

 DOI: 10.1016/j.quascirev.2022.107471

 Artwork by M. Antón

 

Highlights: 

• Previous interpretations have shown sabre-toothed felids with exposed upper canines.

• Our study combining fossils and extant specimens reveals a different life appearance.

• In Homotherium the upper canines had been covered in life when the mouth was closed.

• Smilodon would show visible upper canines when the mouth was closed.

Abstract

Homotherium is one of the sabre-toothed felid genera with a more extensive overlap in space and time with species of our own genus Homo, who must have been familiar with the animal, but now we only have its fossil remains to infer its life appearance. A revised reconstruction of the soft tissue and life appearance of Homotherium latidens is proposed here on the basis of new observations on the anatomy of extant carnivorans and a re-evaluation of the fairly preserved skull and mandible from the classical Late Pliocene site of Perrier (France). This fossil specimen provides some of the best information available about the morphology of the skull and mandible. Like other large early specimens of Homotherium, it has enormous upper canines relative to skull size and high-crowned enough to protrude beyond the lips in the living animal. On the other hand, observations of facial expressions in living big cats and dissected specimens show that, contrary to previous conclusions, the soft tissue around the mouth and the lower lip in particular can cover the upper canines of large felids, even when those are considerably high-crowned. Such observations lead us to propose a revised hypothesis about the life appearance of Homotherium and other sabre-toothed carnivorans, where the upper canines may have been covered in life when the mouth was completely closed.

 Keywords: Plio-Pleistocene transition, Paleoclimatology, Global, Data analysis, Paleobiology, Anatomy, Felidae

Reconstruction of Homotherium latidens based on the fossil specimen MNHN.F.PET 2000 a & b from Perrier:
(A), lateral view of skull and mandible with slight restoration of the ventral outline of the mental crest, and cervical column (this latter a schematic outline based on fossils from Senèze and Incarcal); (B), outline of cranio-cervical skeleton, showing the attachment areas of selected muscles including the temporalis (t), masseter (m), digastric (d) and levator nasolabialis (ln); (C), reconstruction of selected elements of soft-tissue anatomy including the muscles temporalis (t), masseter (m) and digastric (d), as well as the bisected nasal cartilage (nc) and the bisected mass of connective tissue rostroventral to the mental region of the mandible (ctm); (D), reconstruction of the superficial craniocervical musculature, showing fibres of the levator nasolabialis muscle (lnf) and of the orbicularis oris (oof); (E), reconstructed external appearance of the head and neck.

 (Artwork by M. Antón)

Reconstruction of Homotherium latidens based on the fossil specimen MNHN.F.PET 2000 a & b from Perrier:
(A) and (B), perspective view of skull from CT scan, and reconstructed head; (C) and (D), frontal view of idealized virtually sculpted skull and reconstructed head (Artwork by M. Antón). (E) and (F), perspective view with a relaxed expression comparable to that observed in modern tiger (Panthera tigris) shown in Fig. 2J; (G), lateral view of a yawning animal comparable to that observed in modern male lion (Panthera leo) shown in Fig. 2A; (H), lateral view of animal with slightly open jaws and lips contracted in a growling gesture comparable to that observed in modern lioness (Panthera leo) shown in Fig. 2D.

 (Artwork by M. Antón)

Mauricio Antón, Gema Siliceo, Juan F. Pastor and Manuel J. Salesa. 2022. Concealed Weapons: A Revised Reconstruction of the Facial Anatomy and Life Appearance of the Sabre-toothed Cat Homotherium latidens (Felidae, Machairodontinae). Quaternary Science Reviews. 284, 107471. DOI: 10.1016/j.quascirev.2022.107471

[PaleoBotany • 2014] PaleoBiogeography of the Lotus Plant (Nelumbonaceae: Nelumbo) and Its Bearing on the Paleoclimatic Changes

Fig. 2. The distribution of fossil records of Nelumbo on modern world map.

DOI: 10.1016/j.palaeo.2014.01.022

Highlights

• This paper provides additional descriptions to Nelumbo changchangensis He et Jin.

• The historical biogeography of Nelumbo is reconstructed by fossil records.

• Nelumbo distributions in geologic past are linked to climatic changes.

• The origin of lotus tubers is related to cooling climate and increasing seasonality.

Abstract

The historical reconstruction of the origin and dispersal of plant taxa in space and time facilitates a better understanding of their modern distribution patterns. However, most studies of paleobiogeography have focused on terrestrial plants, and the distribution changes of aquatic plants are less well understood. Here we study the lotus plant Nelumbo (Nelumbonaceae), an aquatic perennial herb, with a disjunctive distribution across East, South and Southeast Asia-North Australia and North America. The reproductive organs of Nelumbo changchangensis He et Jin from the Eocene of Hainan, China are supplementarily described. Analysis of the spatial and temporal distributions of Nelumbo in the geologic past indicates that the genus first occurs in mid-latitude area of Laurasia in the Early Cretaceous, then becomes widespread in North America and Eurasia and expands into South America during the Late Cretaceous, and reaches its maximum northern limit during the Eocene. The genus persists and thrives in North America and Eurasia until the Pliocene. The Pleistocene ice age causes the extinction of Nelumbo in Europe and central Asia, and its populations in North American and Asia are also restricted to refuges of lower latitude. Like the terrestrial plants Metasequoia (Cupressaceae) and Nordenskioeldia (Trochodendraceae), the fluctuations of Nelumbo distribution ranges are also linked to climatic changes in the Cenozoic. The cooling climate and increasing seasonality in the Eocene of East Asia may favor the origin of tubers and the differentiating of the ecotypes in lotus, which allow the deciduous type to survive in cold winters.

Keywords: Paleobiogeography; Paleoclimatic change; Lotus; Nelumbo; Nelumbonaceae

Fig. 1. The present disjunctive distribution of Nelumbo.

DOI: 10.1016/j.palaeo.2014.01.022

Ya Li, Thierry Smith, Popova Svetlana, Jian Yang, Jian-Hua Jin and Cheng-Sen Li. 2014. Paleobiogeography of the Lotus Plant (Nelumbonaceae: Nelumbo) and Its Bearing on the Paleoclimatic Changes. Palaeogeography, Palaeoclimatology, Palaeoecology. 399; 284–293. DOI: dx.doi.org/10.1016/j.palaeo.2014.01.022

researchgate.net/publication/260044634_Paleobiogeography_of_the_lotus_plant_(Nelumbonaceae_Nelumbo)_and_its_bearing_on_the_paleoclimatic_changes

http://thedragonstales.blogspot.com/2014/02/lotus-occurance-in-fossil-record-has.html