Research

Earth, Atmosphere & Environment Sciences

Title :

Tracing Early-Middle Triassic marine biotic recovery and ecospace utilization through ichnofabric analysis; spiti Basin; Tethys Himalaya, India.

Area of research :

Earth, Atmosphere & Environment Sciences

Focus area :

Geology

Principal Investigator :

Dr. Bhawanisingh G Desai, Pandit Deendayal Energy University, Gandhinagar, Gujarat

Timeline Start Year :

2024

Timeline End Year :

2027

Contact info :

Details

Executive Summary :

The proposal for "Tracing Early-Middle Triassic marine biotic recovery and ecospace utilisation is based on the need to understand the evolution and recovery of life in the aftermath of the Permian-Triassic Mass extinction (PTME) event. The PTME event is the largest mass extinction in Earth's history, causing significant disruption to the marine food web and ecosystems. After the Mass extinction, Early Triassic was characterised by exceptionally high sea-surface temperatures, widespread anoxia, volcanic activity, and global marine acidification. These Early Triassic events delayed and hindered biotic recovery by six m.y., leaving vast ecospaces unused. Later, innovative organisms evolved to fill these empty ecological niches. However, the biotic recovery was incomplete and never fully regained its pre-extinction diversity. Overall, the PTME and Early Triassic biotic recovery of body fossils are well-known; however, the fate of soft-bodied organisms is still a research topic. Mainstream ichnological studies have engaged in illuminating the timing and patterns of ecosystem recovery after the PTME, as it was severely affected by the drastic reduction in marine environments. The survivors had limited ability to create complex burrows, causing the trace fossil diversity and density decline. Global ichnological data sets characterise a mature ichnofauna with a highly developed trophic structure with fully developed tiers during End Permian. In contrast, the absence of permanent complex burrows, the collapse of bioturbation depth, and the absence of mixed layers and shallowing of tiers mark Early Triassic. The Griesbachian-Dienerian boundary witnessed the first peak in ichnodiversity after the mass extinction, with pre-extinction ichnodiversity level restored in spathian. The decline in the ecospace utilisation for shallow- and deep-infaunal tiers recovered in the early smithian. Later, Dienerian witnessed shallow tier becoming abundant throughout the Early Triassic. The alternate hypothesis suggests a collapse in bioturbational depth associated with tier shifting and no loss of complex trace fossils. Thus, We propose to evaluate the role of infaunal species in adaptation to the extinction crisis and subsequent biotic recovery during the early and middle Triassic. Thus, the project will encapsulate long-term changes in ichnodiversity and ichnodisparity during the Mesozoic and, more specifically, stratigraphically continuous Early-Middle Triassic succession of the Indian Himalayas.

Co-PI:

Dr. Anirban Das, Pandit Deendayal Energy University, Gandhinagar, Gujarat

Total Budget (INR):

42,85,480

Organizations involved