Tonight Primeval ITV1 Wales, 7pm A deadly therocephalian
attacks a school, resulting in a full-scale mobilisation of the ARC team to meet the threat of the poisonous reptile.
However, in a recently prepared specimen of the primitive therocephalian Glanosuchus (GS M796), an additional ridge occurs ventral to the nasoturbinal ridge on the lateral wall of the nasal cavity.
Consequently, its capacity to recover respiratory water vapor was probably limited as well, which suggests that the increase in the ventilation rate of this early therocephalian was likely to have been relatively modest.
The gradual expansion of the nasal respiratory chamber therefore suggests that therocephalian ventilation rates were gradually expanding as well, which is consistent with the increasingly mammallike composition of this group (Kemp 1982, 1986).
As in the therocephalian Glanosuchus, the ridges in Massetognathus are situated within the respiratory chamber, in front of the primary palate.
At present, the earliest evidence for elevated respiration rates is found in Glanosuchus, a primitive therocephalian of the middle Late Permian (approximately 260 million yr ago).
Stance and gait in the hind limb of a therocephalian mammal like reptile.
The skeleton of a baurioid therocephalian therapsid from the Lower Triassic (Lystrosaurus zone) of South Africa.
Several newly prepared fossil specimens are described, which suggest that respiratory turbinals did, in fact, occur among therocephalians and cynodonts, two groups of advanced therapsids.
Both remaining groups of therapsids, the therocephalians and the cynodonts, became increasingly mammallike in appearance during their evolution.