Response to Sirenians (dugongs & manatees)
CreationWiki response: (Talk.Origins quotes in blue)
GAP: The ancestors of sirenians are not known. No sirenian-like fossils are known from before the Eocene.
This one starts with a gap. This means that sirenians make a sudden appearance in the fossil record.
- Early Eocene -- fragmentary sirenian fossils known from Hungary.
- Prorastomus (mid-Eocene) -- A very primitive sirenian with an extremely primitive dental formula (including the ancient fifth premolar that all other mammals lost in the Cretaceous! Could this mean sirenians split off from all other mammals very early on?) The skull is somewhat condylarth-like. Had distinctive sirenian ribs. Not enough of the rest of the skeleton was found to know how aquatic it was.
Prorastomus is based on an incomplete skeleton, that being a skull, a vertebra and some ribs. It seems to be similar enough to a recent find called Pezosiren portelli to suggest that they may be the same created kind. Pezosiren portelli and prorastomus have been placed in the order of Sirenia, but this seems to be more the result of evolutionary influence than anything else. Prorastomus is sufficiently fragmented that it cannot be determined from what was found whether or not it was aquatic. Its similarities to Pezosiren portelli suggest that Prorastomus was a land animal, thus removing it as a potential link between modern sirenians and land animals. Furthermore, Prorastomus and Pezosiren portelli are dated to about the same time with Prorastomus actually considered older, thus eliminating it as a link between Pezosiren portelli and modern sirenians.
Furthermore, even a casual comparison between Pezosiren portelli's skeleton and that of a manatee or sea cow shows that any claim that Pezosiren portelli was a sirenian is bogus. The skulls of both sea cows and manatees have a similar morphology with a clear downward curve in the snout, while Pezosiren portelli has a strait snout. There are also significant differences in the shoulder blades. While there are similarities in rib cage, there are difference as well. Furthermore, there are no transitional forms between Pezosiren portelli and true sirenian. As such, while Pezosiren portelli was clearly a land animal, the only connection with sirenian is in the imaginations of evolutionists.
- Ironically Pezosiren portelli is called "Macro-evolution at its finest." If that is the case, evolutionists have nothing, since it is the only possible link to modern sirenians; Prorastomus is considered older and too incomplete to make a case. It is also thought that Prorastomus was a land animal like Pezosiren portelli.
- Reference: Geotimes - December 2001 - Sea Cow
- Protosiren (late Eocene) -- A sirenian with an essentially modern skeleton, though it still had the very primitive dental formula. Probably split into the two surviving lineages:
1. Dugongs: Eotheroides (late Eocene), ...
2. Manatees: Sirenotherium (early Miocene);...
Protosiren, dugongs, and manatees are clearly the same created kind. Prorastomus's relationship is questionable at best due to the incompleteness of its skeleton and it is probably a land animal of the same created kind as Pezosiren. This is a case of lining up two vaguely similar but different created kinds by way of incomplete fossils.