Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Were they developed anew or a heritage from fish?

share|improve this question

Pangolin scales are certainly not retained from fish. Pangolins are within the clade Pholidota (Tree of Life page for Eutheria) and their nearest relatives are anteaters, sloths, and armadillos.

According to the University of California Museum of Paleontology, similarities between pangolin and armadillos are the results of convergent evolution. So the pangolin scales are a new feature that arose somewhere on the lineage leading to pangolins.

share|improve this answer
    
were they developed from hair or from skin folds? – Anixx Feb 23 '12 at 2:05
1  
They are keratinous scales, like hair and claws/nails. I'd suspect similar development to nails, but I'm not sure. – kmm Feb 23 '12 at 3:41
    
Their closest relatives are carnivores, not anteaters, sloths, and armadillos. See DOI: 10.1186/1471-2148-6-93. – mgkrebbs Dec 22 '15 at 17:23

The pangolin scale is a horny derivative of the epidermis. It is complex in structure and is divisible into three distinct regions. The dorsal plate forms approximately one-sixth of the scale thickness. It is composed of flattened solid keratinized cells without basophilic nuclear remnants. This region tends to fray easily. The dorsal plate contains bound phospholipids and sulphydryl groups but is weak in disulphide bonds. (On the nature of the horny scales of the pangolin)

Also,

It is suggested on the basis of histological structure and dishribution of chemical constituents that pangolin scales are probably homologous with primate nails.

Sorry, I forgot the second part of your question - were they developed from fish. The article suggests that they did NOT evolve from reptile scales. Since fish are even farther removed from reptiles on the evolutionary scale, I think that pretty much answers your question; pangolin scales do not share a common origin with fish scales.

share|improve this answer
    
I don't think this answers the question – rg255 Dec 22 '15 at 13:46
    
Oops - I forgot the second part of his question. I edited my answer accordingly. – David Blomstrom Dec 22 '15 at 16:33

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.