Vertebrate fossil in central Triassic limestone in Vietnam

In late February and early March 2000, Cuc Phuong National Park in collaboration with the Hanoi Geological Museum organized a study on the field of vertebrate fossils on limestone cliffs in Cuc Phuong National Park.

Glutinous sticky rice in layered limestone

Fossils show up on the thin, dark gray limestone cliffs of the Dong Giao Formation, the age of Trias T2. The exposed part of the fossil is a 70cm long spine of 18 vertebrae, 12 of which are intact. The vertebrae of the middle pillar, concave, 3.5-4cm long, the diameter of the vertebral body 2.0-2.5cm; The diameter of the stem is 2.0-2.2cm. Along with the vertebrae, there are two short clavicle. An unclear structure, which looks like a "fin bone" structure, 4 sharp ribs about 4cm long, some of these bones are also scattered on the stone. Observe that some fragments show a clear bone structure.

On the route to the fossil storage site, geologists have combined observations of sediment and structural signs on limestone as well as the expression of morphological signs and plant parts.

Diagram of fossil distribution on the surface of limestone

From the above observations, geologists have initial comments as follows:

1. This is the true fossil of a marine invertebrate buried in the Middle Trias marine sediment T2, about 200-230 million years ago. Based on the backbone morphological locations, it is not possible to immediately confirm this fossil is fish or reptile fish. Because the vertebrae are characterized by fish, the clavicle and ribs carry signs of reptiles.

2. However, whether it is fish or reptile, this is still a vertebrate animal fossil discovered for the first time in Triassic sediments in Vietnam. This finding is meant to create a premise for the expansion of the study, and the discovery of continued fossil animal fossils living in these formations in other parts of our country. The presence of fossils and special geological signs in limestone of Dong Giao Formation will increase the value of research and sightseeing of the national park when designing sightseeing routes and research here.

3. For all of the above reasons, geologists need to protect the status quo in the field, study the details of existing fossils; study and search fossils in limestone of Dong Giao Formation in Cuc Phuong National Park, repair and preserve fossils according to outdoor museum process

Fossils in limestone

Fossils in limestone