Which one contains the thecodonts ?

Options

A. Lacertilia
B. Crocodilia
C. Anopsida
D. Ophidia

Answer

To determine which group contains thecodonts, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Term "Thecodont":**
- Thecodonts refer to a type of tooth attachment where the teeth are firmly anchored in sockets (alveoli) within the jawbone. This is in contrast to other types of dental attachments like acrodont (teeth sitting on the surface) and pleurodont (teeth attached on one side).

2. **Identify the Options:**
- The options provided are:
- A) Lysophilia
- B) Crocodylia
- C) Anapsida
- D) Ophidia

3. **Analyze Each Option:**
- **Lysophilia:** This group includes lizard-like animals, typically having pleurodont or acrodont teeth, not thecodont.
- **Crocodylia:** This group includes crocodiles and alligators, which possess thecodont teeth. Their teeth are firmly rooted in sockets in the jawbone.
- **Anapsida:** This group includes turtles and their relatives, which generally have pleurodont or acrodont teeth, not thecodont.
- **Ophidia:** This group includes snakes, which also have acrodont or pleurodont type of dentition.

4. **Conclusion:**
- Based on the analysis, the group that contains thecodonts is **Crocodylia** (option B).

### Final Answer:
The group that contains thecodonts is **Crocodylia**.

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