Answer:
No. Dinosaurs are a group of ancient reptiles that
had a set of particular skeletal features. The hips,
hind legs, and ankles were specialized and allowed the
legs to move directly under the body, rather than
extending out from the side of the body as in modern
lizards. This arrangement enabled dinosaurs to bring
their knees and ankles directly below their hips and
provided the necessary attachments for very strong leg
muscles. Dinosaur skeletons were well designed for
supporting a large body, for standing erect (upright),
and for running.
The
front legs were adapted for grasping prey, for
supporting weight, or for walking and running. The
skulls of dinosaurs were designed for maximum
strength, for minimum weight, and (in some cases) for
grasping, holding, or tearing at prey. These skeletal
features separated dinosaurs from other ancient
reptiles such as Dimetrodon, the plesiosaurs, and
pterosaurs. Fossil mammals, like mammoths and
"saber-toothed tigers" (e.g., Smilodon), are also
often incorrectly called dinosaurs.

These ancient animals are NOT dinosaurs!