Crocodyliformes | Reptiles

 

Did you know that Crocodyliformes are the closest living group to 'Dinosaurs' ?

Crocodyliformes comprises of all the Modern crocodilians (crocodiles, Alligators, Caimans & Gharials ) and few other closely related crocodile - like reptiles which are all extinct now.

Have you ever heard that crocodiles never shed 'tears' like me ? Well they sort of do while eating !!

Many animals including humans have a thin layer of water over their eyes called "Tear Film". This layer keeps the eye safe from pathogens and provides nutrients and performs many different functions in each animals. This tear film is secreted by the Tear Glands. For example in some birds this layer protect their eyes from all kinds of particles of dust and dirt and many pollutants. In Crocodilians too it has it's own set of unique purposes. One of them is to maintain clear vision even when their eyes are submerged because without a tear film, their eyes would dry out quickly underwater. This would lead to irritation, discomfort, and ultimately, blurry vision. When these crocodilians swallow their food whole the tear glands get pressed and eject lot of tear into their eyes, which gives the impression of crying. The tears of crocodilians are known to be extremely moisturous and does not dry out easily. the tear film consists of a combination of proteins and water along some some other cellular essentials necessary for the cells in that particular tissue (eyes). That unique combination of proteins turned out to be a great binding substance which could potentially be an ingredient of many artificially made substances/chemicals .

** Since Crocodiles most of their time under water unlike humans who blink frequently to spread tears across their eyes, crocodiles can go for long periods without blinking and don't have to rely on clear water for hunting. For example Caimans can upto hours without blinking even on land!!

The 'Tear Film' of the crocodilians are highly inert and long lasting. The special composition of the tear film consisting a combination of proteins act as Binding agents which make the film a lot stable. **

Another prominent feature of these crocodilians is that of their "Digestive System", it's 'stomach' to be specific. Crocodilians (all of them) have a anatomically modified stomach, which is of two chambers. These chambers are called "Fundic" and "Pyloric" respectively. The most remarkable feature is that, crocodiles swallow their prey  whole (no Mastication) the food directly enters the Fundic chamber of the stomach where it is chemically decomposed or digested. In a way crocodilians actually breakdown their food chemically than before mechanical breakdown (which takes place later in the pyloric chamber).

Crocodilians live in and near water bodies for the majority of their life even though they possess a pair of lungs. They can stay for longer period of time under water completely submerged holding on to their breath. They are the "Apex predators" of their ecosystem and are cold- blooded animals (Ectotherms) i.e they are the group of animals whose body conditions are largely influenced by their surroundings. ( such as internal temperature, pH and Salinity levels in bodily fluids etc)

Among all the features of the crocodiles such as strong jaws, Huge bite force, it's predatory lifestyle and it's ambush attacks, lies one peculiar feature that is less known. Crocodiles swallow stones !!
These stones provide a supplementary force of buoyancy due to their weight which aids these creatures to balance and maneuver their bodies underwater.

I hope that you enjoyed and learned something new today also help spread this blog encouraging me to write more and more simplified Zoology for you !!

By,
J. Maanavendra roy,
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(Checking reliability) Citations :- 

• About stomach chambers
  Takasaki, R., & Kobayashi, Y. (2020). Stomach histology of Crocodylus siamensis and Gavialis gangeticus reveals analogy of archosaur “gizzards”, with implication on crocodylian gastroliths function. Acta Herpetologica, 15(2), 111–118. https://doi.org/10.13128/a_h-7564
  
  
• About their 'tears'
  "The conclusive research in 2006 has for now ended the debate and it was proved that crocodiles indeed weep while they eat as there is an aggressive movement in their jaws while they chew their food which stimulates their tear gland, the researchers opined."
  
  - neurologist D Malcolm Shaner and zoologist Kent A Vliet filmed.
  
  

   Some ancient and extinct groups of crocodyliforms.