Sitting Buddha Images in Thailand

Subduing Mara (Calling the Earth to Witness). Observe the sitting posture of the Buddha. The RIGHT leg is folded over the left leg. The soles of both feet are upward. This is most correctly called the half-lotus posture (compare with full-lotus posture below). Other names used for this posture are : 'hero posture' or virasana (paryankasana).

Meditating in the full-lotus posture. This is also called the diamond posture. Other names used are 'adamantine pose' or Vajrasana. Each foot is resting on the opposite thigh, right leg crossed over the left leg. Notice that the soles of both feet are visible. While not that common in Thailand, a Buddha image seated in this way is more likely to be observed in the North of the country, and is common in India.
Do not practice this in one go at home!
Buddha image at Phra Pathom Chedi, Nakhon Pathom.

Buddha image at Wat Pa Lelai, Suphan Buri. The Buddha sits in the so-called European pose. The legs simply hang down (like most of us sit on a chair). Another name for this pose is pralambapadasana.
The hand gesture that the Buddha at Wat Pa Lelai uses is quite uncommon (left hand with palm on the knee, right hand slightly lifted above he right knee, palm down) and is described as displaying the attitude of jungle life.

Stone carving of scene from the Buddha's life. Dvaravati art 7th-11th century A.D. The Lord Buddha is seated in so-called 'European' fashion.
Phra Pathom Chedi National Museum (Nakhon Pathom)
Original found at Wat Sai, Nakhon Pathom.