Question

put the fossils in order from earliest (oldest = 1) to most recent (youngest = 7).
lucy
triceratops
trilobite
archaeopteryx
synapsid
ptilophyllum
skate

Explanation:

Step1: Determine the geological time periods of each fossil

• Trilobite: Paleozoic era (very early).
• Synapsid: Paleozoic era (later than trilobite).
• Ptilophyllum: Mesozoic era (earlier part of Mesozoic).
• Archaeopteryx: Mesozoic era (later part of Mesozoic, related to early birds).
• Triceratops: Mesozoic era (late Mesozoic, dinosaur).
• Lucy: Cenozoic era (early hominid).
• Skate: Cenozoic era (still exists, recent in terms of fossil comparison as it's a modern - like form).

Step2: Order based on time periods

Starting from the oldest (Paleozoic earliest) to youngest (Cenozoic latest).

Answer:

1. Trilobite
2. Synapsid
3. Ptilophyllum
4. Archaeopteryx
5. Triceratops
6. Lucy
7. Skate