In the Cretaceous non-avian dinosaurs died out all in one morning.
The cerebral peduncles are structures at the front of the midbrain which arise from the front of the pons and contain the large ascending -LRB- sensory -RRB- and descending -LRB- motor -RRB- nerve tracts that run to and from the cerebrum from the pons .. pons. pons. cerebrum. cerebrum. midbrain. midbrain. Mainly , the three common areas that give rise to the cerebral peduncles are the cerebral cortex , the spinal cord and the cerebellum .. cerebral cortex. cerebral cortex. spinal cord. spinal cord. cerebellum. cerebellum. The cerebral peduncle , by most classifications , is everything in the midbrain except the tectum .. midbrain. midbrain. tectum. tectum. The region includes the tegmentum , crus cerebri and pretectum .. tegmentum. tegmentum. crus cerebri. crus cerebri. pretectum. pretectum. By this definition , the cerebral peduncles are also known as the basis pedunculi , while the large ventral bundle of efferent fibers is referred to as the cerebral crus or the pes pedunculi .. cerebral crus. cerebral crus. The cerebral peduncles are located on either side of the midbrain and are the frontmost part of the midbrain , and act as the connectors between the rest of the midbrain and the thalamic nuclei and thus the cerebrum .. cerebrum. cerebrum. midbrain. midbrain. thalamic nuclei. thalamic nuclei. As a whole , the cerebral peduncles assists in refining motor movements , learning of new motor skills , and converting proprioceptive information into balance and posture maintenance .. proprioceptive. proprioceptive. Important fiber tracts that run through the cerebral peduncles are  : cortico-spinal , cortico-pontine , and cortico-bulbar tracts .. Damage to the cerebral peduncles results in unrefined motor skills , imbalance , and lack of proprioception .