HOME | DD

Description
The sizzling Early Eocene sun shines down on an open tract of land on the edges of a Brazilian tropical forest. The 18m long, heavily built Saltasaurid Titanosaur Itaboraititan browses nonchalantly, taking no notice of the array of smaller animals that have gathered in its wake. A beast of this size brings with it a certain set of benefits that the whole ecosystem can profit from. Parasites and detritus lodged on the Sauropod's back provide food for a flock of Allotodus; these tiny, sparrow-sized Enantiornithines are descendants of the Late Cretaceous Alexornis and are stem members of the highly diverse Order Alexornithiformes. Meanwhile, the tramping footfalls of the behemoth loosen up the dry top soil, pushing burrowing invertebrates closer to the surface. Enterprising animals have learned to take advantage of this. The pig-like Notosuchian Sarculosuchus digs down into the earth searching for worms, roots and tubers, while the basal Paleognath Protinamus probes the soil for insects.

Other creatures are simply going about their daily business, knowing that there is nothing to fear from their giant neighbour. A ruddy Sciurailurus lounges on a branch, catching the last of the early morning sun. This vaguely Condylarth-like animal is actually a member of the diverse Eutherian clade Cimolesta and demonstrates some features not seen in Northern Hemisphere relatives. Like many of South America's mammals, the ancestors of Sciurailurus are descended from North American ancestors that island hopped their way southward during the Late Cretaceous and Early Paleocene. Now isolated on a verdant, tropical continent, small insectivorous Cimolestans began to evolve in unusual directions. Sciurailurus is a rather large, omnivorous/frugivorous mammal with broad, flat molars, enlarged canines and flexible ankle joints usual for a scansorial existence. Other notable North American immigrants include Metatherians. These adaptable therians first appear in the South American fossil record during the Early Paleocene and, right from the beginning, they radiated in an explosive manner. Two of these can be seen on the second highest branch. The cat sized, long bodied Sparassodont Pinheirolestes hunts the tiny, insectivorous Sansanodelphid Riodelphopsis.

However, not all South American mammals were derived from relatively recent ancestors. Older stalwarts, such as Dryolestoids, were still present in force and can be split into two broad groups. The first, the probable wastebasket taxon Leonardoidea, were comprised of generally small, insectivorous and omnivorous forms, are represented here by Quadratodon. This long tailed, white furred mammal has a highly flexible diet and is theorized to be semi-arboreal. The representative of the latter group is the herbivorous Brasiliungulatum planidens, a very large, dog-sized Mesungulatoid. Indeed, Brasiliungulatum is the largest mammal known from Eocene deposits anywhere in the world. While smaller Mesungulatoids were exceeding common, B. planidens is only known from a single partial skeleton which reveals an animal with heavily worn molars and a reinforced spine. These adaptations are quite similar to these of the Cimolestan Taeniodonts, suggesting a similar lifestyle of scratch digging for roots and tubers. Later Mesungulatiods generally became smaller and more cursorial as time went on, leaving B. planidens as a curious Paleogene side branch.

Description
The sizzling Early Eocene sun shines down on an open tract of land on the edges of a Brazilian tropical forest. The 18m long, heavily built Saltasaurid Titanosaur Itaboraititan browses nonchalantly, taking no notice of the array of smaller animals that have gathered in its wake. A beast of this size brings with it a certain set of benefits that the whole ecosystem can profit from. Parasites and detritus lodged on the Sauropod's back provide food for a flock of Allotodus; these tiny, sparrow-sized Enantiornithines are descendants of the Late Cretaceous Alexornis and are stem members of the highly diverse Order Alexornithiformes. Meanwhile, the tramping footfalls of the behemoth loosen up the dry top soil, pushing burrowing invertebrates closer to the surface. Enterprising animals have learned to take advantage of this. The pig-like Notosuchian Sarculosuchus digs down into the earth searching for worms, roots and tubers, while the basal Paleognath Protinamus probes the soil for insects.

Other creatures are simply going about their daily business, knowing that there is nothing to fear from their giant neighbour. A ruddy Sciurailurus lounges on a branch, catching the last of the early morning sun. This vaguely Condylarth-like animal is actually a member of the diverse Eutherian clade Cimolesta and demonstrates some features not seen in Northern Hemisphere relatives. Like many of South America's mammals, the ancestors of Sciurailurus are descended from North American ancestors that island hopped their way southward during the Late Cretaceous and Early Paleocene. Now isolated on a verdant, tropical continent, small insectivorous Cimolestans began to evolve in unusual directions. Sciurailurus is a rather large, omnivorous/frugivorous mammal with broad, flat molars, enlarged canines and flexible ankle joints usual for a scansorial existence. Other notable North American immigrants include Metatherians. These adaptable therians first appear in the South American fossil record during the Early Paleocene and, right from the beginning, they radiated in an explosive manner. Two of these can be seen on the second highest branch. The cat sized, long bodied Sparassodont Pinheirolestes hunts the tiny, insectivorous Sansanodelphid Riodelphopsis.

However, not all South American mammals were derived from relatively recent ancestors. Older stalwarts, such as Dryolestoids, were still present in force and can be split into two broad groups. The first, the probable wastebasket taxon Leonardoidea, were comprised of generally small, insectivorous and omnivorous forms, are represented here by Quadratodon. This long tailed, white furred mammal has a highly flexible diet and is theorized to be semi-arboreal. The representative of the latter group is the herbivorous Brasiliungulatum planidens, a very large, dog-sized Mesungulatoid. Indeed, Brasiliungulatum is the largest mammal known from Eocene deposits anywhere in the world. While smaller Mesungulatoids were exceeding common, B. planidens is only known from a single partial skeleton which reveals an animal with heavily worn molars and a reinforced spine. These adaptations are quite similar to these of the Cimolestan Taeniodonts, suggesting a similar lifestyle of scratch digging for roots and tubers. Later Mesungulatiods generally became smaller and more cursorial as time went on, leaving B. planidens as a curious Paleogene side branch.