CORDIS - Forschungsergebnisse der EU

Ecological diversity of land vertebrates through the largest extinction in Earth history

Periodic Reporting for period 1 - ECODIV (Ecological diversity of land vertebrates through the largest extinction in Earth history)

Berichtszeitraum: 2022-03-01 bis 2024-02-29

Contemporary Earth’s ecosystems are threatened by accelerating extinction rates, but their responses to biodiversity losses are not detectable on short-time scales. However, large-scale biodiversity crises, or ‘mass extinctions’, occurred in the past and their long-term effects are detectable and measurable in the fossil record, although still poorly understood. For example, the origin of modern-style ecosystems can be linked to the most severe biodiversity crisis in Earth history at the Permian-Triassic boundary (PTME; ~252 million years ago). This event caused the disappearance of over 70% of vertebrate species but the extinction, land community of the Triassic were transformed, and entire new groups of animals diversified to exploit ecological roles that did not exist in Permian ecosystems. This hints that extinctions may play a fundamental role in driving evolution altering the evolutionary trajectory of ecosystems by altering the composition of ecosystems and by favouring an increase in ecological complexity. Nevertheless, the ecological impacts of mass extinctions and biodiversity crisis on ecosystems are still poorly understood.
ECODIV, aims to explore these gaps of knowledge and to develop methods to describe patterns of ecological diversity approaching, during and in the aftermath of the PTME. We to targeting gaps in the fossil-record using on fiedlwork and repository data of exceptionally well-preserved and well-sampled ecosystems.
Using these data ECODIV aims to establish new methods to quantify and compare patterns of ecological diversity in deep-time that will be used to assess the appearance/disappearance of major groups and their ecological roles in ecosystems across different phases of the PTME.
The aims of the outgoing phase were to collect the data and develop the methods study the ecological structure of deep-time ecosystems. They have all been achieved.

Work Package 1. Data collection and preparation.
Task 1.1. We compiled lists of species occurrences of well-preserved and well-sampled ecosystems Permian and Triassic assemblages worldwide using a fieldwork data, literature, online repositories, and museum collections. We assembled ~50 datasets that include data that are regularly ignored (i.e. incomplete specimens, microfossils, footprint) in broad diversity studies.
Task 1.2. The researcher participated to fieldwork campaigns with the group of the outgoing phase host targeting Triassic geological formations of the southwest USA (Arizona, Texas, New Mexico). We filled a major low-latitude gap in the fossil record by collecting new data from the Middle Triassic Moenkopi Formation of Arizona and creating of a new collection of Moenkopi Formation vertebrates (over 100 vials of microfossils and 4 full drawers of specimens that will be accessioned to the Utah Museum of Natural History), and redescribed Anisodontosaurus (one of the first reptiles to experiment with herbivory in the Triassic).
- Revision of the fossil record of the Moenkopi Formation: creation of a new collection based on fieldwork-collected data (description in progress), and redescription of Anisodontosaurus
- Completion of abundance dataset for the Triassic of Arizona (508 specimens; 5 time-bins, with information on locality and age) (support WP3–4)
- Completion of southwest USA dataset (150 species; 13 time-bins, geological age, formation (support WP3–4)
- Datasets of species occurrence in ~40 vertebrate assemblages (10 South Africa; 18 Russia; 1 Tanzania; 1 Madagascar; 3 India, 3 China, 2 Germany, 4 Brazil, 5 Argentina) (support WP3–4)
- Use of online repositories (e.g. Paleobiology Database)
- Training in fieldwork, laboratory and curation techniques

Work package 2. Ecological modelling and analysis
Tasks 2.1. We created a method that transforms occurrence data collected in WP1 into ecological data – a necessary step to quantify metrics of ecological diversity in assemblages. We started scoring each species in each assemblage for five ecological traits (body size, diet, habitat, locomotion, growth). We used these data to quantify metrics of ecological significance for each assemblage (e.g. diversity, richness, disparity, redundancy). During the outgoing phase we prioritised scoring assemblages from the Triassic of the USA, because of the availability of relevant collections, however, we began to compile datasets for the other ~40 other Permian-Triassic assemblages worldwide. Overall, 23 assemblages are completed and 24 more are in progress.
Task 2.2. We developed the methods and codes to calculate ecological variables that together describe the ecological properties of assemblages.
- Ecological data collected for 23/~50 assemblages (>300 species) (support WP3–4)
- Multivariate representations of 13 assemblages (support WP3–4)
- Codes to calculate 4 ecological variables (e.g. diversity, richness, disparity, redundancy) (support WP3–4)
- Ecological modelling
- Resampling techniques and coding in R

Work package 3. Ecological impact of the PTME
WP3 has not progressed as originally planned because we prioritised WP4 instead. The progress made in WP1,2,4, means that WP2 is nearly ready to start.

Work package 4. Recovery phase.
Task 4.1. We calculated the ecological variables (e.g. diversity, richness, disparity, redundancy) of 13 Triassic assemblages in the southwest USA. This allowed us to investigate the recovery phase at unprecedented geographical and stratigraphic scales. Preliminary data indicate that Middle Triassic ecosystems of North America were taxonomically and ecologically depleted compared to Late Triassic equivalent ones.
- Patterns of ecological diversity and species richness through the recovery phase in North America
- Resampling techniques and coding in R

Exploitation and dissemination
Progress and results were disseminated via: 1 in a peer-review publication, two conference attendance (1 conference oral presentation and 1 in-person invited presentation; 3 outreach events; 2 outreach online talks; via social media and a dedicated webpage on the researcher's website.
ECODIV is producing new primary data (new fossil collections) and creating new tools to study biodiversity in deep-time. The sampling strategy of the project includes data that are largely ignored (e.g. footprints, incomplete and/or indeterminate specimens), meaning that our project produce a more accurate representation of proportion of biodiversity than previous methods. ECODIV focus on well-sampled assemblages is key to understand evolutionary and ecological phenomena at the scale they take place, accounts for biases, and improves the resolution of the results.
By the end of the project metrics of ecological importance (ecological diversity, richness, disparity etc.) will be calculated for >50 assemblage and major vertebrate groups. The analyses will track the evolution of groups and ecological roles, patterns of diversity leading and during the PTME and during the recovery to a degree that has never been achieved before
Ultimately, this project assesses the responses of terrestrial ecosystems to drastic environmental perturbations and thus methods and results may be adapted to inform future conservation efforts.
The lower jaw of Anisodontosaurus greeri an herbivorous reptile from the Middle Triassic of Arizona