Macrocollum suture. "Macrocollum", alongside "Jaklapallisaurus" and "Unaysaurus", was found to belong to the clade Unaysauridae. "Macrocollum" lived between about 225.42 to 225 million years ago, in the Norian age of the late Triassic period. It was found in the south of Brazil, which at the time was connected to northwest Africa. At the time, most of the Earth's landmass was united into the supercontinent Pangaea, which was just starting to divide into Laurasia in the north, and Gondwana in the south. U-Pb (Uranium decay) dating found that the Caturrita Formation dates to around 225.42 million years ago, making it fewer than
Gondwana and barren landscape. West Gondwana drifted north during the Devonian which brought Gondwana and Laurasia close together. Global cooling contributed to the Late Devonian extinction (19% of marine families and 50% of genera went extinct) and glaciation occurred in South America. Before Pangaea had formed terrestrial plants, such as pteridophytes, began to diversify rapidly resulting in the colonisation of Gondwana. The Baragwanathia Flora, found only in the Yea Beds of Victoria, Australia, occurs in two strata separated by or 30 Ma; the upper assemblage is more diverse and includes Baragwanathia, the first primitive herbaceous lycopod to evolve from the zosterophylls.