Tree Crocodile

 Tree Crocodile

Habitat: Long Island; Lower Swamps
Type: Semi-Arboreal Crocodile
Length: 10 to 15 Feet
Weight: 200 to 400 Pounds

The Tree Crocodile is one of the more unusual reptiles found in the swamp forests of Lower Long Island. While it is clearly a crocodile, its behavior sets it apart from anything else in its family. It is not truly specialized for any one environment, but instead functions well enough in three—water, ground, and trees.

Adult In Tree

Its body is lighter and more flexible than fully aquatic crocodiles. Its limbs are longer, and its claws are stronger and more curved; allowing it to climb when needed. This is similar to the Sand Croc juveniles on Midway Island. Even so, adult Tree Crocodiles are not especially fast or agile in the trees. As large as they are, climbing is slow and deliberate, and the animals show clear selectiveness in how and where they ascend.

The Tree Crocodile favors thick trunks with rough bark, often those that grow at a slight angle, making access easier. It climbs by gripping with its foreclaws and pushing upward with its hind legs, moving in a steady, crawling motion. Progress is slow, and the animal frequently stops to rest. It rarely climbs higher than twenty feet or so, and once in position, it stays close to the trunk or on large, stable branches capable of supporting its weight.

Still, this limited climbing ability works well enough for its purposes. The trees are not a place of movement, but of ambush.

Most hunting is either done on the ground or from low branches. On the ground, it feeds on smaller animals—reptiles and amphibians that live along the swamp floor. Common prey includes the Square Turtle, the Mud Walker, and the Banded Salamander. These are taken with quick lunges, the crocodile relying on surprise rather than pursuit.

In Its Terrestrial Habitat

Its most notable behavior, though, is its use of the trees for ambush. The Tree Crocodile will climb onto low, sturdy branches and remain still for long periods, waiting for larger animals to pass below. When the opportunity comes, it drops down onto the prey with considerable force and delivers powerful bites. This allows it to take animals much larger than those it could manage on the ground alone. Using this strategy, it often targets the Rabbit Deer, as well as small Parrot Ox or Swamp Moose.

Despite its versatility, the Tree Crocodile must avoid several threats from larger predators. On land, it contends with the Marsh Tiger, a far more capable terrestrial predator. Encounters between the two are dangerous, and the Tree Crocodile will often flee to water or up a tree if given the chance.

However, the waters of the Swamps are home to far more dangerous predators, including the Swamp Crocodile and the Giant Salamander. Because of this, the Tree Crocodile avoids prolonged time in the water, using it mainly as a means of travel between patches of land or to reach trees that stand in deeper areas.

Nesting takes place in the trees. The female selects a sturdy branch or fork and constructs a nest above the swamp floor, where she lays her eggs. This behavior likely protects the clutch from aquatic predators. The young, once hatched, are much more agile climbers than the adults. Juveniles spend much of their early life in the trees, moving with a speed and confidence that is lost as they grow heavier. As they mature, they descend more often to the ground and adopt the slower, more deliberate climbing behavior seen in adults.

Tree-Living Hatchling

• Naturalist Note: The “Tree Crocodile” described here is likely a member of the genus Mekosuchus, a group of crocodilians known from fossil evidence to have been more terrestrial than modern forms. Daniel’s observations suggest an additional behavioral adaptation beyond what is currently understood—namely, limited but functional arboreal activity.

The reported body mass of 200 to 400 pounds is significant. At this weight, complete arboreal specialization would be unlikely. However, the described behavior does not require it. Instead, the animal appears to employ what could be described as facultative climbing—the ability to ascend trees when necessary, without relying on them as a primary habitat.

This is supported by several inferred anatomical traits: moderately elongated limbs, recurved claws, and a lighter overall build relative to aquatic crocodilians. These features would not make the animal an efficient climber, but would allow it to scale inclined or rough surfaces with sufficient stability.

From Daniel's other writings, the giant Swamp Crocodile that poses such a threat in the water is likely Prionosuchus. The smaller, but also aquatic, Giant Salamander is much larger than the true giant salamanders of Japan. More likely, this was something similar to the giant anthracosaur Pholiderpeton. 

The Tree Crocodile's ambush-from-above strategy is particularly noteworthy. While uncommon among reptiles of this size, it is mechanically plausible. A controlled drop from even a modest height would generate substantial impact force, enabling the predator to subdue animals as large as young Swamp Moose (likely the Broad-fronted Moose) and the Parrot Ox (likely a large dicynodont such as Placerias or Kannemeyeria).