150-Million-Year Shell Fossil Cemetery

The search for fossils here began long before the shell find. A Kasetsart University page says that in 1976 Sutham Yaemniyom found Thailand's first dinosaur bone, a sauropod bone, during a uranium survey in Phu Wiang, Khon Kaen. Soon after, the Northeastern geological survey team found dinosaur and crocodile fossils in Nong Bua Lam Phu district, then part of Udon Thani province; the crocodile teeth were later named Sunosuchus thailandicus in 1984.

The site was once a sandstone quarry. The Nong Bua Lam Phu public relations office says blasting exposed a high cliff full of ancient shells; after the quarry was abandoned, villagers found attractive shell-patterned stones and dug out large amounts to sell. Love Thailand says villagers noticed the shell-shaped stones in the abandoned quarry around 1994.

The Department of Mineral Resources later surveyed the site and identified the fossils as bivalves of varying sizes. The provincial public relations office dates them to the Late Jurassic, about 150 million years ago, which gave the place its name; Love Thailand gives about 140–150 million years.

Later research paints a different picture. Sakboworn Tumpeesuwan's 2010 Chulalongkorn University PhD thesis studied 16 freshwater mollusc taxa from 12 localities in Nong Bua Lam Phu, Phu Wiang and Sahat Sakhan in the Sao Khua Formation and placed them in the Early Cretaceous, with the upper Sao Khua in the Late Barremian, about 125–130 million years ago. It named a new species, Pseudohyria (Matsumotoina) somanai, the first record of that subgenus in Thailand. A 2024 paper in Tropical Natural History lists Ban Huai Duea among the conglomeratic-sandstone shell beds of the upper Sao Khua Formation, so the "150 million years" in the name reflects the older dating.

These were freshwater river mussels. The same 2024 study examined a similar shell bed at Phu Kum Khao in Roi Et and interpreted it as sediment washed over a meandering river's banks; that bed also yielded freshwater hybodont shark teeth, fish bone, theropod teeth and sauropod bone fragments, a glimpse of Isan's river plains in the age of dinosaurs.

The Sao Khua Formation was named in 1964 by Ward and Bunnag. It is the middle unit of the Khorat Group, lying on the Phra Wihan Formation and under the Phu Phan Formation, about 120 m thick, made of sandstone, conglomerate, siltstone and reddish-brown claystone. English Wikipedia summarises it as a floodplain crossed by large meandering channels. It is one of Thailand's key dinosaur formations, with Phuwiangosaurus, Siamosaurus, Siamotyrannus and Kinnareemimus, plus ancient crocodiles, several freshwater shark genera and the bivalve Pseudohyria (Matsumotoina) somanai.

Other animals of the same age have been found here too. Love Thailand reports ancient crocodile remains and dinosaur bones in a layer about 2 m above the shell bed, including upper forelimb and lower hindlimb bones, a shoulder blade, finger bones and ribs. Matichon (2017) also reported a dinosaur skeleton and freshwater shark remains at Ban Huai Duea, and stone slabs in a small cave that ring like a drum when struck.

The single-storey exhibition building has a King Naresuan shrine in front. The provincial public relations office says it covers the universe, the solar system, the origin of life, evolution, dinosaurs and the fossils found at Ban Huai Duea, a replica of the cliff, how palaeontologists work, and tourist information for each district. Love Thailand mentions a model of Siamotyrannus isanensis about 4 m high and 7 m long, a carnivorous dinosaur discovered in the Sao Khua Formation at Phu Wiang, Khon Kaen.

Highway 210 in front of the museum has its own dinosaur story. MGR Online reported on 24 April 2006 that rock cutting for the Nong Bua Lam Phu–Udon Thani road at km 30 in Nong Bua subdistrict uncovered many herbivorous dinosaur fragments scattered over about 1 km². The contractor had to work carefully with Department of Mineral Resources staff on watch, and geologist Pratchaya Bamrungsong from Phu Wiang examined the site. The province asked people to return fossils they had taken, and many villagers did; rumours of dinosaur eggs were dismissed as round stones passed off for sale.

On 8 August 2020 the province opened the "Dino Park" in the museum grounds. Isan Daily Online reports deputy governor Wiangchai Kaewpinit presided; the 5-rai park has 10 moving dinosaur models, 36 dinosaur eggs, an artificial waterfall and a tram, built with 39,460,000 baht from the Upper Northeast provincial cluster budget.

Nong Bua Lam Phu also gave its name to a new dinosaur species. Thai PBS reported on 12 November 2019 that the Department of Mineral Resources announced Vayuraptor nongbualamphuensis, Thailand's 11th dinosaur. Its bones were found in 1988 in Phu Kao–Phu Phan Kham National Park by Phaladet Srisuk; about 130 million years old, it was a medium-sized carnivore about 4–4.5 m long with slender hind legs, named after Vayu, the wind god, plus the Latin raptor. English Wikipedia also records the freshwater sharks Isanodus and Lonchidion from Phu Phan Thong in the province.

Nong Bua Lam Phu has other fossil finds. Matichon reported in August 2017 that staff clearing a cliff at Phu Phan Noi found petrified wood shaped like a stump with roots, about 1 m long; the provincial administration chief estimated it at least 100 million years old, though this was unverified and a Khon Kaen geologist was to examine it. Naewna reports dinosaur fossils about 130 million years old at another site, Ban Huai Sai in Nong Bua subdistrict.

Finds keep coming. Spring News reported on 13 July 2023 that villagers foraging in the hills near Ban Huai Sai, Nong Bua subdistrict, found many bones in limy sandstone. The Department of Mineral Resources' Region 2 office made a preliminary identification of three dinosaur groups, a sauropod-like plant-eater, a fish-eater and a meat-eater. The bones are kept at Wat Pa Huai Sai Thong Nak Chai Phon, and villagers hope for a museum.