Monday, February 6, 2012

Evolutionary Background and Taxonomy

First things first, my blog is slightly deceiving… the “Seagull” depicted’s name isn’t actually seagull, but Larus occidentalis, or a Western Gull. This is the species name, or the most specific way of categorizing a creature. Taxonomy can be a very confusing so as a little review, the different aspects of categorization are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (want an easy way to remember this? Just remember “Dumb kids playing chicken on freeways get squished!”). When applying this to the seagull we all see on the beach, the taxonomy is:

- Domain: Eukaryota

- Kingdom: Animalia

- Phylum: Chordata

- Class: Aves

- Order: Charadriformes

- Family: Laridae

- Genus: Larus

- Species: Larus occidentalis

Other gulls are part of the Laridae Family: Genus Ichthyaetus, Leucophaeus, Chroicocephalus, and others, making them all very close relatives. Although some posts in this blog (like this one!) will focus on either larger or more specific aspects of gulls, it will primarily focus on the Larus genus of the Laridae family.

The evolutionary background of the Aves Class is actually very interesting in that it highlights their evolutionary similarities to reptiles and dinosaurs. One of the most important finding that caused this bird-dinosaur hypothesis was that of the 150-million year old Archaeopteryx (check out the picture below!). This oldest bird on record had one essential characteristic that identified it as a bird: feathers. This clinching characteristic of a bird was found alongside reptilian jaw bones and an extended boney tail just like a reptile. In addition to this ancient bird’s similarities with reptilian dinosaurs, other similarities between the first birds and dinosaurs include (but are not limited to): eggshell microstructure, ankle held above the ground (you might think a bird’s knee is backwards, but that is actually because it isn’t it’s knee, but it’s ankle!), hollow bones, large eye openings in the skull and s-shaped curved neck. From these incredibly early beginnings, the bird evolved into an extremely diverse group with a variety of features that evolved dependent on naturally selected capabilities to succeed.

Think it looks anything like a Seagull??

2 comments:

  1. Very interesting, but no facts different from other sights I've seen. Nothing Unique:(

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  2. it's okay. but it needs more info

    ReplyDelete