Which of the following pairs are correctly matched ?
$\begin{array}{cccc}& \text{Animals}& & \text{Morphological features}\\ \text{(i)}& \text{Crocodile}& -& \text{4-chambered heart}\\ \text{(ii)}& \text{Sea urchin}& -& \text{Parapodia}\\ \text{(iii)}& \text{Obelia}& -& \text{Metagenesis}\\ \text{(iv)}& \text{Lemur}& -& \text{Thecodont}\end{array}$

Exceptionally, crocodile has four-chambered heart. In Obelia the alternation of generation is called metagenesis in which an asexual polypoid generation appears to alternate regularly with a sexual medusoid generation. Thecodont dentition is found in mammals.