Final answer:
The statement that not all thyreophorans can be assigned to the stegosaurs or the ankylosaurs is false. Stegosaurs and ankylosaurs both fall under the thyreophoran group, known for armored bodies.
Step-by-step explanation:
The statement that not all thyreophorans can be assigned to the stegosaurs or the ankylosaurs is false. Thyreophorans are a group of ornithischian dinosaurs known for their body armor, which includes both stegosaurs and ankylosaurs. The stegosaurs are distinguished by their rows of distinctive plates and spines along the back, while the ankylosaurs are recognized by their heavily armored bodies and often a club-like tail.
Although the thyreophoran group is distinct because of their well-defined physical characteristics, which helps in their categorization, there have been instances in paleontology where new dinosaur discoveries cannot be immediately classified into existing groups due to incomplete fossils or unique features. Nevertheless, these unclassified specimens are often later found to fit within the broader established categories of stegosaurs or ankylosaurs or represent transitional forms within the thyreophoran lineage.