TTFG: Marshosaurus

Marshosaurus bicentisimus
“Speedy carnivorous pack-hunter”

Size: 16 feet long, weighing 1 ton

Diet: Dryosaurs (small herbivores), camptosaurs (beaked dinosaurs), hesperosaurs (stegosaur relatives), young sauropods (long necked dinosaurs), eggs

Habitat: Floodplains, fern savannas in Western North America, mainly Colorado

Time Period: Tithonian stage of the Late Jurassic, 150-145 million years ago

Appearance: A standard megalosauroid (lightweight carnivorous dinosaur), Marshosaurus is a medium-sized speedy hunter. Marshosaurs are usually seen living in packs coordinated mainly of females and their offspring, while the males usually roam around, never more than a few miles from the presence of a female pack. Males are ruddy brown or mottled green, with a slightly paler underbelly. Females are rather drab; a uniform muddy brown. The chicks are covered in mottled brown and green fuzz, which acts as camouflage in their environment.

Behavior: Fierce pack hunters, the smaller females often surround their prey on all sides, taking turns lunging, snapping, and clawing at their quarry, a technique that causes their prey to die of blood loss. Many scientists have quoted that female marshosaurs are rather patient with their prey, being able to wait for more than several hours before making the final killing blow. Males, on the other hand, are solitary, and, even alone, they can attack full grown Hesperosaurus due to their bulkier build. Greeting ceremonies in a pack are elaborate, with many interactions that includes head bobbing, gentle head bumping, scents, grunts, and growls. These ceremonies can often be heard more than 3 miles away, attracting attention from roaming scientists in the field.

Reproduction: As stated above, males are solitary and only interact with others of their kind during breeding season. In August, the male goes into a hormone-induced state, following a female and gently, then hardly, bumping her with his snout. He’ll often bite her as well on the flanks, and many females have deep scars from the accidentally painful pressure of these bites. The male is polygamous (mates with several individuals), and goes off to find another female to mate with. When females are sought by two males, the latter gender will battle like Spartan warriors, bloodthirsty and proud. These fights often end at the death of one or both battlers. In mid-September, the eggs are laid in a heap of rotting vegetation on a forest’s edge, which the pack never strays far from. At four years, the young usually leave to start their own packs.

Danger Level: Medium-High: Marshosaurus females usually do not attack unless one is in the presence of chicks, but males can and will charge you. As long as you flee like a frightened little toy-cup poodle or escape up a tree you should be fine.

Note: Marshosaurus often fall victim to the plundering of allosaurs. These fights can be gory and interesting to observe, as a pack of three to five female Marshosaurus, each 15 long, gang up and injure a pair of 30-foot allosaurs.