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whales

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India's Pig

Fig. 1 Digital texture. Adobe Photoshop

How could a small deer-like artiodactyl be related to the largest animal ever


Indohyus, meaning "India's pig" is thought to be the oldest relative of whales. Discovered in  Eocene deposits of the Himalayas, this small animal was once thought to be a distant relative of pigs. The original fossils were discovered by Ranga Rao in 1971 in the Dehra Dun region of India. As a side note, George Harrison recorded a song about this area. 

Rao died before completely describing the fossil material and it seemed the secerets of "India's pig" were buried along with him. But in 2007, Rao's widow gave the fossils to legendary anatomist Dr. Hans Thewissen to analyze.

By accidentally breaking the cranium, Dr. Thewissen discovered Indohyus had the same ear bones as do all modern and extinct whales. This meant that the racoon-sized Indohyus was in the whale family tree. It is rare fossil discoveries like this that have lead scientists to piece together the whale evolutionary lineage. The fact so many rare cetacean fossils have been found in the right place at the right time is unique in the history of evolutionary discoveries. Further analysis of Indohyus revealed it was actually thick boned (osteosclerotic), which also meant it was fully aquatic. Perhaps this allowed the animal to leap in the water to evade predators, much like modern chevrotains do.

 

How I Did It

Understanding that Indohyus could've been nocturnal, much like chevrotains, I wanted to create a night scene for this reconstruction. After making a few quick drawings, I decided on this pose (Fig. 2)  because it showed off the most notable anatomical features of the animal: The long face and long hoofed limbs. Additionally, it presented an opportunity to showcase a bit of inferred behavior.

Fig. 2 Graphite, oil, & ballpoint pen on paper. 

Once I had the right pose drawn out, I scanned the drawing and layered digital fur(Fig. 3).  Once I had the whole animal textured, it was time to work on the background.

Fig. 3 Fur texture detail

Fig. 3 Fur texture detail

I began with a perspective layout matching the rough drawing (Fig4). This would serve as the foundation for forest texture (Fig. 5). 

Fig. 4 Digital layout in Adobe Photoshop.

Fig. 5 Background texturing process

It was then a matter of compositing Indohyus into the background. This part was a little bit tricky because I had to match the light source and darken appropriate areas. Too much dark would obscure the fur details and too little contrast would remove visual emphasis. After experimenting with a few levels, I settled on a balanced look. 

Fig. 6

I wasn't too satisfied with the red tint because it didn't convey the colors of night. I changed the hue and felt it was a more proper fit for the scene. 

Fig. 7 Indohyus in its new home

 

References

Bajpai, S; Thewissen, JG; Sahni, A (November 2009). "The origin and early evolution of whales: macroevolution documented on the Indian subcontinent". J Biosci. 34 (5): 673–86. doi:10.1007/s12038-009-0060-0. OCLC 565869881. PMID 20009264

Rao, A Ranga (1971). "New mammals from Murree (Kalakot Zone) of the Himalayan foot hills near Kalakot, Jammu and Kashmir state, India". Journal of the Geological Society of India. 12 (2): 124–34.

Sample, Ian. "How Bambi Evolved into Moby-Dick." The Guardian.com. N.p., 19 Dec. 2007. Web. <https://www.theguardian.com/science/2007/dec/19/whale.deer?gusrc=rss&feed=networkfront>.

 

 

 

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When Whales Walked

Fig. 1   Graphite, ballpoint pen and oil on paper. 


Natural History

Ambulocetus natans was an early whale ancestor capable of moving on land and underwater.  Named from an almost complete skeleton from Pakistan, A. natans was sea lion-sized and likely ambushed its prey. Since it did not have a tail fluke, this amphibious cetacean ancestor used its prominent hind limbs as oars to propel itself underwater. Its dense limb bones(osteosclerotic) tells us that it moved well in estuarine habitats, but was probably clumsy on land. Its face was long, and crocodile-like, with eyes set dorsally and probably fed by drowning larger prey. 

It was an important discovery in piecing together the cetacean family tree, as it showed how whales went from "land-lubbers" to blubber-laden fully aquatic ecomorphs.

How do we know it was a whale? The one feature that consistently unites whales and their kin are the ear bones (auditory bullae) and A. natans is no exception. Analysis of its ear reveals that Ambulocetus heard well underwater.

 

How I Did It

I wanted to show Ambulocetus in its element using the latest science. I began with a rough gesture drawing (Fig. 1) to which I then added digital textures in Photoshop. To understand the surface anatomy better, I created a muscle reconstruction (Fig. 2). 

Fig. 2  Color pencil & ballpoint pen on paper; digital colorization in Adobe Photoshop.

Understanding of the musculature allowed me to work out lighting over the forms better. Although the coat pattern of Ambulocetus is speculative, I was inspired to use facial markings similar to those of modern whales. Lastly, I wanted to add very contrasted lighting for two reasons: 1.) to simulate the soft shadows seen in murky underwater photographs 2.) represent the former "mystery" of whale evolution and consequent "light" of discovery  brought about by Ambulocetus.

 

Fig. 3 The finished piece:&nbsp; Ambulocetus  takes a lungfish prey

Fig. 3 The finished piece: Ambulocetus takes a lungfish prey

 

 

References

Kemp, T. S. (2005). The Origin and Evolution of Mammals (PDF). Oxford University Press. ISBN 0-19-850760-7. OCLC 232311794. Retrieved June 2016. 

Konami Ando, Shin-ichi Fujiwara, Farewell to life on land – thoracic strength as a new indicator to determine paleoecology in secondary aquatic mammals.

Thewissen et al. 2009, Ambulocetidae: the First Marine Cetaceans.

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