The animals were in plastic boxes hidden under containers filled with fruit in a six-wheel truck being searched at a checkpoint on Phetsakem road in Muang district, army unit leader Theeraporn Boonsue said.
The search found 1,580 turtles hidden in 158 boxes and 34 pangolins in six containers at the bottom of the freight compartment, Sub Lt Theeraporn said. The animals were seized and handed over to the province's wildlife office.
Thanaporn Suksawang, who drove the vehicle, denied any knowledge of the animals, saying he was ordered by his boss to pick up fruit from Sungai Kolok district in Narathiwat province to deliver to Talad Thai in Phathum Thani province on a return trip from taking vegetables to Pattani buyers.
Sub Lt Theeraporn said his account was not convincing.
A phone call was made to the driver during the interrogation during which 100,000 baht in cash was offered in exchange for the release of the truck and the driver.
Authorities randomly check trucks which could be used by traffickers to transship rare animals by covering them with fruit during the harvesting season in the southern region.
The seized turtles could have earned the traffickers 3 million baht if the driver had been able to deliver the animals to buyers, he added.
The demand for turtles and pangolins is high in China where many believe the meat contains medicinal qualities.