In mammals, the brain is developed in three regions&colon; the forebrain, midbrain, and the hindbrain. The previously mentioned markers for forebrain and hindbrain are physically localized, appearing in clusters. Markers for forebrain and hindbrain can also be tested. Like in "Jainosaurus" and most other non-avian archosaurs, the hindbrain and midbrain of "A." sp. The pons and the hindbrain lie caudally to the VTA. Motor neurons produced in the hindbrain have Tbx20 selectively expressed. During pregnancy, all the fetuses in the trial had hindbrain herniation. For example, ATRA plays an important role in activating Hox genes required for hindbrain development. Krox20 gene expression is restricted to the early hindbrain development. These mice are unable to survive after birth and exhibit major hindbrain defects. In the hindbrain, segmentation is a precisely defined process. The hindbrain (or metencephalon) is particularly involved in swimming and balance. It also plays a large role in deciding the structure of the mid- and hindbrain. The hindbrain or metencephalon is particularly involved in swimming and balance. In the hindbrain these are known as rhombomeres.