Sea cow used for Iban hilts
 

I just had three Swedish and German blade smiths visiting me to study some of my Indonesian and Filipino blades. We had a great time and I also learned a lot on how some of my blades were made, why it has this or that shape and how some of the twist core and laminations are done etc.
One eye opener for me was that two of my Iban hilts are made of sea cow bone, not antler as I always considered all Dayak hilts to be made from without even reflecting about it. Actually when it was brought up it was easy to spot the other hilt as the colour is totally different than from the whiter antler hilts.
By coincidence (or maybe not?) both of them are Iban/Sea Dayak and both of them are on Langgai Tinggangs.
Maybe someone else will discover this material on their hilts too?

Michael

Michael

Very nice hilt. What tells you it is sea cow and not antler apart from the colour which could just be a factor of age and use ? or is this another definite / maybe scenario ?

I have something which looks similar, I always thought it was antler, but now you have me doubting :confused:

Regards
Roy

Interesting Michael!

I noticed the different in colours of "antler" handles before, but I always thought it might be that the antler had different colours by itself?
I've seen them by very "teeth"white to very darkbrown. A friendcollector told me once that the whiter pieces have seen a lot more sun as the pieces with darker handles which probably were more used in the forests as in open area where sunlight was shining.....(but I don't know if this is true and what his source was for this statement).

Let's suppose this would be sea cow, from which part could it be than?
Is there also seen a difference in material/structure, besides of the colour?

Maurice

According to the smith that used sea cow for his knife handles it's both the yellow surface layer as well as the spongy parts inside that characterize it as sea cow.
If I remember him correctly it was the top part of the back bone used for the first hilt (Maybe I need to recheck this with him or let him answer directly when he is back home again in Germany tomorrow night?).

Michael

VERY INTERESTING!! I HAVE ALWAYS ADDED THE FACTS ON THE SIZE OF SEA COW TEETH TO ELIMINATE THE POSSIBILITY OF THEIR BEING BIG ENOUGH TO MAKE IVORY KERIS HILTS OR MOST OTHER HILTS.
USING SEA COW BONE HAS NOT COME UP BEFORE BUT AS THE ANIMAL IS LARGE AND THE BONES LARGE ENOUGH AND DENSE ENOUGH FOR USE AS MANDAU HANDLES AND OTHER ITEMS AS WELL. THE SEA COW HAS BEEN HUNTED FOR A VERY LONG TIME AND IS STILL HUNTED IN MANY AREAS. TODAY IT IS HUNTED FOR FOOD IN MOST REGIONS WHERE IT OCCURS.
SO IT IS LIKELY THE BONE COULD BE USED AS IT WOULD HAVE BEEN AVAILABLE AND PERHAPS EASIER TO OBTAIN THAN DEER ANTLER FOR VILLAGES NEAR THE SEA AND RIVERS.
A LOCAL WHO HAS WORKED WITH ANTLER AND SEA COW WOULD BE ABLE TO TELL THE DIFFERENCE BUT I WOULD NOT BE ABLE TO AS ALL I HAVE STUDIED HAS BEEN FOSSILIZED. THANKS FOR THIS INTERESTING POST IT IS NEW KNOWLEGE TO ME. :)

Given the nature
 

Given the nature of practices of old and the easy availability of bone, could these hilts not be Human bone :shrug:

Hello Michael,

Can this smith send examples of seacow bone for comparisson ?
To me almost all bones are spongy inside. and colour can be influenced by a lot of things.
It would be interesting to know if there is a very clear difference in structure.

Ps. if he uses seacow bone, is this new or old ? aren't seacows protected species ?

Best regards,
Willem

I am not denying the possibility of this, however i'm not sure that i am prepared to accept this without question based on the identification od a single smith who has used the material in his own blades. As has been mentioned, just about all bone and antler has a spongy appearance on the interior and color is very dependent upon environmental circumstance.
Now, if you can get a marine biologist to make the same ID.... :shrug: :)

It being summer, I'd suggest taking this piece to the nearest large natural history museum or major university with a large zoology department. In your country, that is (see last paragraph). What you want is someone with a dugong skeleton on hand, to compare the piece with.

The issue is that most of it is so sculpted that it will be difficult to tell if it is a dugong vertebra (top of the back) or not, without that same vertebra to compare it in three dimensions (which willl present an opportunity for some great photos, incidentally). Oddly enough, museums tend to have such skeletons around, or to know who does have them. In my experience, if they're not too busy, they also enjoy puzzles like determining the source of a bone.

I'm a little puzzled, because dugong ribs (not vertebrae) have a reputation for being unusually dense. So far as I know, they act to ballast the animals in the water. Unfortunately, it's been handled so much that non-destructive DNA sampling will simply pick up human DNA.

As for legal status, yes, dugongs are in Appendix 1 of CITES, which is the most restrictive one.

Best,

F

sea cow hilts
 

thank you for sharing this,i will have to dig out my dyak swords and have a closer look,i never knew before reading this post that they used sea cow i also assumed it was stag they were made from . regards napoleon

IN MANY PARTS OF THE WORLD PEOPLE LIVE THE WAY THEY ALWAYS HAVE IF THEY CATCH A SEA TURTLE OR SEA COW THE FAMILY EATS WELL. BUT MOSTLY THEY LIVE ON MORE SIMPLE OR BLAND FARE. I HAVE SEEN BOTH SEA TURTLE AND DUGONG SKELETONS IN TRASH HEAPS IN SEVERAL PLACES SOME THINGS NEVER CHANGE.
I AM DEFINITELY FOR PROTECTING ENDANGERED SPECIES BUT I CAN'T BLAME A MAN LIVING IN A PRIMATIVE SOCIETY FOR TAKEING WHAT NATURE HAS BROUGHT HIM AND HIS ANCESTORS TO FEED THEIR FAMILIES. OFTEN THE LAW TAKES THIS INTO CONSIDERATION AND SOME TRIBES ARE ALLOWED TO HUNT AND TAKE A CERTIAN PROTECTED SPECIES IN REGULATED NUMBERS SO THE POPULATION IS NOT IMPACTED MUCH.
I DO HATE TO SEE SOMETHING USEFUL AND COOL THROWN INTO THE TRASH HEAP, OR LAYING BY THE ROADSIDE TO ROT AND WASTED BUT THATS THE LAW. :shrug:

Vandoo,

I don't blame anyone for making a hilt out of a bit of bone, either, and I wouldn't be surprised if it was made before dugongs were listed as endangered species (in 2000, AFAIK).

The issue here is that, depending on the customs agents of a particular country and the amount of documentation VVV has, if this langgai tinggang crosses a border, it might get confiscated. That's the reality of living in a world where many really cool species are endangered.

The reason I mention this is that I know people in England who would love this puzzle. I'd hate to tell VVV to take this blade to them, only to have it confiscated in transit. That benefits no one, not even the remaining live dugongs.

My 0.0002 cents,

F

Interesting info. I work a lot with natural materials (antler / bone). There are numerous difefrences among species. If you look at the range of antlers: they vary from very porous (european deer) to completely dense (elk / axis / reindeer / ...). Regarding the sea cow: I have a big chunk at home / will take some pictures. Stellar sea cow is allready extincted / lots of their bones are found in norhern regions and can be used without problem.

.

Obviously this thread caught some interest so I will contact him on Sunday and ask him to join this discussion so you get his arguments directly from him.

I don't know any marin biologist myself but if there is one on the list, or a member knows one good enough, maybe you can ask him for a comment too?

Unfortunately it isn't that easy to walk around with a large head hunter sword in central Stockholm and draw the blade among 100's of people inside the natural history museum during the tourist season without getting trouble with the police. :D

On the use of human bones I have never seen or heard about it being used for mandau hilts, unlike skulls placed under the main pillars of the long houses. Probably because of that it doesn't match the Dayak belief system.

On transit hassles fortunately there are no customs between EU-countries (Sweden - UK). Otherwise it might be a problem even if I have never experienced it myself as I only buy blades from before the ban.

Michael

Regarding the use of human bone for a mandau handle:

http://www.vikingsword.com/vb/showth...ghlight=mandau

Yes, I remember that old thread and I have handled the mandau IRL.
But as far as I remember later on it was discovered that it wasn't human bone ...

Michael

Hi Michael,

A couple of points.

One is that you neither need nor want a marine biologist, since they typically work with fish (or worms, or whatever). You want an vertebrate anatomist or a paleontologist--a bone dude (or dudette). They typically work at museums, veterinary schools, and universities. Look for places with lots of nicely mounted skeletons.

With regards to carrying a blade around, I've used poster tubes to carry swords (jian), but all you need is a bag that disguises the sword's shape and makes you look harmless. Perhaps a guitar case?

Cheers,

F

Michael,

What was it discovered to be? I ask as many of your hilts show a patina found on very old and well handled human bones but then the practice of head hunting was pretty quick and I am sure they didn't hang around to take other limbs...of maybe they did now and then?

Gav

Bone density might be the answer here. Dugong are not deep diving sea mammals so thier bones are more dense than whales. As they live in water they have less dense bones for buoyancy. Land mammals have heavier dense bones certainly bones big enough for sword handles will be hard and dense. So if the bone is light and spongiform it may well be Dugong. Some interesting stuff on bone to follow when an item finishes on ebay.

Gav, it was over 6 years ago I was offered it (May 2005 according to my files). Probably I wanted to have proof that it was human bone and didn't get it?
I just remember that we agreed on that it wasn't human bone for sure after all and I bought some other mandaus instead.

Michael

Ben, aka Dajak who posted the thread above that Gustav linked to, just mailed me.
He wrote that he later had showed the mandau to a surgeon who told him that it was human bone and might be from an arm. So maybe there is at least one mandau with a hilt made of human bone after all out there...

Michael

IT IS LIKEY THERE ARE NO CITES EMPLOYEES IN THE WORLD WHO COULD IDENTIFY A MANDAU HANDLE MADE OF SEA COW BONE AND LIKELY NONE WHO COULD EVEN IDENTIFY A COMPLETE SKULL. I WOULD THINK A LARGE RIB BONE WHERE IT CONNECTS TO THE SPINE WOULD BE OF THE RIGHT SHAPE AND SIZE FOR A MANDAU HANDLE.
I COULD ID A COMPLETE SKULL BUT NOT A PIECE OF CARVED BONE, I CAN ALSO ID HUMAN BONE IF THERE IS ENOUGH OF ITS ORIGINAL SHAPE REMAINING BUT A SMALL CARVED FRAGMENT ONLY CAN BE DONE IN A LAB EQUIPPED TO DO SO. SO AS LONG AS SEA COW OR ANY OTHER FORBIDDEN ITEM IS NOT MENTIONED IT SHOUILD PASS WITH NO PROBLEMS. I WOULD BE MORE CONCERNED IN SOME COUNTRIES WITH THEFT BY POSTAL EMPLOYEES OR CUSTONS AGENTS.
THE PROBLEM IS ALL PEOPLE WORKING IN THESE TYPE JOBS ARE TRAINED TO LOOK AT ALL OF THE GENERAL POPULATION AS A GUILTY SUBSPECIES AND THE ENEMY. UNFORTUNATELY SOME PEOPLE DO FIT THIS TYPE BUT MOST DO NOT.
THIS USED NOT TO BE THE CASE AS THEY WERE JUST TRAINED TO UPHOLD THE LAWS AND SERVE THE PEOPLE BY UPHOLDING THOSE LAWS. IF A PERSON STOPPED ALONGSIDE THE ROAD AND TOOK SOME FEATHERS FROM A DEAD BIRD THAT HAPPENED TO BE AN EAGLE IN THE OLD DAYS IF A WARDEN SAW THIS HE WOULD CONFISCATE THE BIRD WARN THE PERSON ASSUMING HE WAS NOT A POACHER BUT IGNORANT OF THE LAW AND THAT WOULD LIKELY BE THE END OF IT. TODAY THE PERSON WOULD BE PROSECUTED AND FINED TO THE FULL EXTENT OF THE LAW AND WOULD LIKELY SPEND MORE TIME IN PRISON THAN A MURDER. NOT BECAUSE THEY REALLY BELIEVED HE WAS A PROFESSIONAL EAGLE POACHER OR TO SERVE THE LAW JUSTLY BUT TO MAKE AN EXTREME EXAMPLE AND SET A PRECIDENT FOR FUTURE CASES.
IN THEIR DEFENSE MOST AGENTS ARE NOT LIKE THIS EVEN THOUGH THEY ARE OFTEN EDUCATED TO BE. BUT THERE ARE AGENTS OUT THERE WHO ARE BAD APPLES AND LIKE TO USE THEIR POWER TO CAUSE PEOPLE GREIF AND IF YOU RUN AFOUL OF ONE YOU WILL BE CONSIDERED GUILTY AND BAD NO MATTER WHAT YOU SAY OR DO SO EXPECT NO MERCY.
I WORKED WITH THE CURATORS OF A NATURAL HISTORY MUSEUM IN HOUSTON TEXAS AND FOUND ALL OF THEM TO BE GOOD PEOPLE AND FAIR AND REASONABLE BUT THAT IS NOT ALWAYS THE CASE.
I SENT AN ARTEFACT TO A LOCAL EXPERT AT A LOCAL COLLEGE FOR HIM TO GIVE AN OPINION ON. THE FELLOW I SENT IT WITH CAME BACK AND SAID IT WAS AN ATAL ATAL HANDLE OVER 10 THOUSAND YEARS OLD AND WAS MADE OF HUMAN BONE SO THE PROFESSOR HAD CONFISCATED IT AS PEOPLE WERE NOT ALLOWED TO HAVE HUMAN REMAINS.
IF ASKED I WOULD HAVE GLADELY DONATED IT TO THE UNIVERSITY COLLECTION BUT WHEN TREATED LIKE A LOOTER ALTHOUGH IT WAS A SURFACE FIND IN A RIVER AND WOULD HAVE BEEN DESTROYED SOON HAD I NOT FOUND IT. SO GET TO KNOW PEOPLE BEFORE YOU TRUST THEM BECAUSE CREDENTIALS AND DIPLOMAS DO NOT NECESSARLY INDICATE A GOOD MAN.
SUCH IS LIFE YA TAKES YOUR CHANCES. :shrug:

( SKULLS UNLIMITED ) IN OKLAHOMA CITY HAS EXAMPLES OF SEA COW AND MANATEE AND OTHER SKELETIONS (ALL LEGAL} THEY ARE A GOOD REFRENCE
, THEY USE THEM TO MAKE GOOD REPLICAS TO SELL. THE OWNER WOULD KNOW HOW TO ID THE BONES IN THE SKELETON BUT I DON'T KNOW IF HE COULD TELL MUCH LOOKING AT A MANDAU HANDLE.? I WILL HAVE A TALK WITH HIM WHEN I GO OVER FOR A VISIT NEXT TIME. YOU CAN GOOGLE SKULLS UNLIMITED FOR A LOOK AT HIS CATALOG ON LINE IF INTERESTED.

A SPECIALIST IN SEA COW WOULD BE ONE STUDYING THE CLASS SIRENIA TO WHICH IT BELONGS ALONG WITH THE MANATEE. THE STUDY OF WHALES (CETACIANS) MAY OVERLAP SO SPECIALISTS SHOULD BE OUT THERE ESPECIALLY DUE TO THE INTREST IN THE AMERICAN MANATEE.

Since you found the need to comment on my suggestion i must point out that a paleontologist is in no way a "bone dude", but one who studies paleontology, the study of all prehistoric life forms, both plant and animal and their fossilized remains.
A marine biologist is involved in the study of the origins, behavior, diseases, genetics, and life processes of animals and wildlife of the marine environment. It's a big ocean and i am sure that marine biologists specialize in certain sub-categories of their field, one of which would certainly include the study of marine mammals, Sea Cow included.
A vertebrate anatomist might be helpful, but frankly i am having a hard time finding any specific information on exactly what they do... :shrug: :)

My sister-in-law is a prof emeritus in vertebrate anatomy, but she reckons she has very little knowledge of anything at all to do with marine mammals. Suggests that it could be a special field --- whatever that might mean.

Well, I can call someone a paleozoologist, but the way it tends to work, if you're a paleontologist, you typically study vertebrates. Otherwise, you're a paleobotanist, an invertebrate paleontologist, a paleoecologist, a paleoclimatologist, or whatever.

Go read the tetrapod zoology blog if you want to get an idea of what they do and what they're interested in.

That said the question is, is the bone from a dugong. There are a couple of ways to figure that out:
--destructively, with DNA sampling (bore into the bone, away from the surface treatment)
--non-destructively, by figuring out what bone it is (most likely rib or large vertebra) and matching it to the corresponding piece of a skeleton.

That's why you want a comparative anatomist. Paleontologists use this skill all the time, because typically, they get bits of bones from unknown organisms, and have to figure out not only what bone they have, but what the organism was and what it looked like. That's effectively the puzzle you have here.

So yes, you want a bone dude(or dudette). Preferably, you want an institution that has a dugong skeleton to hand, so you can figure out which bone it was by lining it up against the unaltered version. If it's not a dugong, the choices get interesting. Whale? Dolphin? Rhinoceros? Horse? Bovine? Human? There aren't a huge number of large-boned animals in that part of the world, so you should be able to work it out.

F

It might even be stag from the sambar deer :) ;)

Given that the hilt is firstly just a small part of the bone (if indeed it is bone and not antler) and then it is extensively carved i am afraid i cannot see any possibility that it could be matched to any existing whole bone for verification. Even when paleontologist work for fairly intact bones they have been know to make mistakes. I don't think there would be enough for them to work from here.

Actually, David, you'd be surprised.

For one thing, you have both the spongy inner core (trabecular bone) and the outer dense cortical bone.

So far as I can tell, it's not carved out of a cylinder, so it's not from the middle of a long limb bone. You can see that because the hilt is curved, but the trabecular bone is only on one corner. Assuming this is a correct observation, the bone came from a bone with a more complex shape, such as the head of a thigh or the vertebra of a very large animal.

The nice thing about bones with complex shapes is that they tend to be distinctive. This means they can be identified.

Without measurements, I can't tell whether this hilt could have been made from a human thigh (my guess is not). However, if you have a bunch of bones to compare it to, you can ask whether the hilt would fit within a particular bone. By process of elimination, you can get an ID.

Additionally, there may be clues in the texture of the bone that will allow it to be identified.

Were I the person with a mystery bone hilt, I'd approach a museum and say that I'm trying to determine the identity of the bone so that I can properly document it for CITES, or some such.

It's always possible that it can't be identified. However, if there's a later question about the identity of the bone (say from customs), you can whip out a letter that says that you took it to a museum, and Dr. Bone-Genius couldn't figure out what it was, except that there's no evidence it's from a CITES covered species, and it's too old to be covered anyway.

Either way, you get something from the exercise.

Best,

F

That's not a bad approach. If i were in NYC i'd probably go to the Museum of natural history where they are likely to have both manatee skeletons AND dayak swords. :)
Michael, do you have a good Natural History museum nearby?

Actually only a 5 minutes walk from the University. But no way I will walk around with an old head hunting sword, first among 1000's of museum visitors and then just as many at the campus. It's enough with those ninja wannabees that you read about in the newspapers now and then running around with practice iai-to and scaring people. :rolleyes:
So I wait for the blade smith working with this material to get back to me, hopefully tomorrow or early next week, so you can read his explanation.
I had around 80+ dayak parang, all of them with patination of different kind, in the room for us to discuss. After he showed me the first one it took me about a minute to spot the second one. None of the other hilts were even close in looks.

Michael

While writing the post above I got the response from the blade maker:

"Colours are so very typical for seacow; the yellow and the fainter brown / yellow are very typical.
The spongiosa is not as it would be with antler; this is bones spongiosa.
The quality of the reflections and polished surface is *absolutely* typical.

I will send you some pictures of hilts I made from seacow ( this was sold as "Steller´s Seacow) - made from the ribs of those animals.
Yours might be of a different species - anyway, I am absolutely sure. Of course I could be wrong, but this is my favourite bone material, and I happen to know it quite well.

I´ll be back with pictures, gimme a few days..
[...] the material I use is very very old and there are no CITES restrictions, as the Steller´s Seacow was obliterated in the 1800´s."

Hi Michael,

I'm telling you, violin and guitar cases were just made for carrying headhunting swords, especially on campus during summer. :D

Better though, it sounds like you have a real expert to tell you what you have. Great news.

Best,

F

Hi Michael,

I strongly doubt the whole Steller seacow story:

A: Its an artic living animal and of course its p[ossible that someone exported the bones to Borneo but actually I don't see any reason for that.
It should make the handle extra expensive while dearantler has almost the same effect.

B: the structure /grain of your examples are following the fork shape while a handle from seacow most likely should have all the grain in one line.

C: dearantler can be enourmous various in quality and color and it looks to me that ( the Kenya like) is carved quite near the spongeous centre.
If you come closer to that centre you have indeed more "bonelike" structure on the surface.

D: What I doubt if a animistic Dayak would easily accept to take a "dead ?'' bone from an animal he doesn't know and carve from that a handle that he carry with him the whole day.
Antler has a special reason as its one of the "fastgrowers" ( like hair, nails,tusks, horn) and so "loaded" with "living power",sometimes also special kinds of wood ( specially shaped roots etc).

E: About that human bone handles, maybe they are human and seacow as well, carved from the bone from an anourmous fat lady.....


:D :D :D

Arjan

Arjan,

On Steller's sea cow he doesn't claim that mine are that, only sea cow. The dugong, the one of the living species closest to Steller's, is found outside Borneo.
I am not a "hilt-material guy" myself so I will probably put you into contact with one that is and then it would be interesting to read your conclusions.
Your words "animistic Dayak" reminded me of an idea I got when he first told me about it being sea cow (Alan, please don't read this because I am speculating based on documented folklore from neighbouring places ;) )
If you are in the forest you want to have hilt material made from wood or a forest animal not to disturb the ruler of the forest. But if you are planning to join a pirate trip on the sea the ruler of the sea would be very angry if you had a hilt from a land based animal on your sword and ship (wood seems to be neutral being found both in the forest and drifting around on the sea).
This corresponds to the beliefs of the Malay fishermen who even had a special language to avoid mentioning land based animals when on the sea not to disturb the ruler of the sea. One version is the one studied (Annandale 1903) in Patani and Pahang where for instance a horse was renamed chehweh dras (= fishing language prefix + fast) and a buddhist monk chehweh kuning (prefix + yellow).

Michael

But that should include that most seadayaks never travelled the sea with their deerantler handled swords and that those with the seacow handled sword never saw their wife and kids on the land.
If I must choose between an angry sea and an angry wife...... Hmmmmm....

Ha, ha, ha, not quite.
Please note that I only found sea cow hilts on the langgai tinggang (= sea dayak war swords), not the ilang (both war and utility swords).
In a way the hypothesis might also explain why you find some very high status parang with wooden hilts.
And as usual with folklore it can be quite local, just a small area. It might even be a requirement from the ship owners according to their beliefs.
But anyway I will try to find time later tonight to check some of my articles and books on Iban customs to see if I find something more about customs at sea.

Michael

IT IS HIGHLY UNLIKELY ANYTHING OTHER THAN DUGONG BONES WOULD BE USED AS THEY ARE THE ONLY MEMBERS OF THIS GROUP OF ANIMALS IN THE REGION AND WERE KNOWN AND HUNTED FOR FOOD. STELLER SEA COW BONES WOULD STILL BE AVAILABLE IN SOME NORTHERN LOCATIONS IN OLD TRASH HEAPS NEAR CAMPS OF WHALERS AND ESKIMOS. THE BONE WOULD NOT HAVE FOSSILIZED AND MAY STILL BE USED BY LOCAL TRIBES??
THE STELLER SEA COW BONES MIGHT BE A BIT LARGE FOR MANDAU HANDLES ANYWAY AS ADULTS WERE AROUND 30 FEET LONG. THERE ARE STILL REPORTED SIGHTINGS IN THE REGIONS WHERE THEY USED TO LIVE BUT NO CONFIRMATION OF ANY SURVIVORS SO FAR.
STELLAR SEA COW SKELETON

For modern hilts, there's a company that's making Alaskan ulus with "mermaid bone" aka Steller's Sea Cow bone. As with fossil mammoth tusks, the material is available. I don't know how far it ships, but I'd be unsurprised to see "mermaid bone" show up in any *modern* hilt.

As for traditional hilts, that's a different issue entirely.

F

Hi Michael,

I'm curious what you will find, I can image that Malay shippers had such requirements but I wonder if already we have problems with seeing the difference the shipper would and if the dayak would tell him the truth.

If the dayak themself had such requirements, I wonder how they should do that if transport on Borneo is mostly over the river.
should they make the difference between river and sea ? ( note that the villages in many cases of the big headhuntingraids where attacked from the sea and following the river upstreams)

other thing is ..do you have a pic of the whole Langgai with that Kenya like handle ? it would be interesting

Arjan

Thanks for publishing the picture of the sea cow skeleton!
It's easy to imagine that if you see such a skeleton on the beach you might think of a sea dragon, if that is a part of your world-view's probabilities.
In Hornbill and Dragon, by Bernard Sellato (1989), his, maybe a bit simplified, cosmology of the Dayak is that the Upperworld is the Hornbill and the Underworld the Dragon. On page 44 he writes "In the arts, other reptilian or aquatic animals - crocodiles, lizards, turtles, snakes, frogs, and fish - are equal to the dragon." On the same page he also claims "The Bornean dragon corresponds to the Indian makara water-monster..."
So why don't we see dragons on the parang hilts? Actually now and then you see a lizard hilt, even if it's quite rare (enclosed are 2 examples from Hornbill and Dragon). And below them is an example of a Makara on an Iban Jimpul from my collection. But these seem to be more of an exception than a rule.

Back to the hypothesis on if Malay beliefs somehow might have influenced Ibans when they started to travel by sea for their raids. I have used some quite old sources to investigate this because already in the late 1800's the British quenched those raids. Actually it was the same time that the Langgai Tinggang and the Nyabur were more commonly used as Iban war swords.
It is evident that the Ibans, who originally came from the inlands of Borneo, became pirating Sea Dayaks (instead of River Dayaks) first after they had contact with the coastal Malays of Sarawak. Here are some supports for this:

"The Dyaks of Sarebas and Sakarran, a brave and noble people, were taught piracy by the Malays who dwelt among them. These Dyaks were always head-hunters, and used to pull the oars in the Malay prahus for the sake of the heads of the slain, which they alone cared for. But, in course of time, the Dyaks became expert seamen. They built boats which they called bangkongs, and went out with the Malays, devastating the coast and killing Malays, Chinese, Dyaks, whoever they met with."
Sketches of Our Life at Sarawak, by Harriette McDougall (1882)

"The Sea Dyak's history likewise shows a growth of headworship parallel to the increasing importance of war. When they were mere agriculturalists. fighting only among one another over disputed ownership of land, they used to take the heads of their enemies slain in these battles; but it was not until the Malays taught them to grow rich by piracy that the passion for head-hunting became deeply rooted, and that they went on expeditions for the avowed purpose of getting heads."
The Influence of War and Agriculture upon the Religion of Kayans and Sea Dayaks of Borneo, by Margaretta Morris (1904).

Below is also enclosed a part copied from On the Wild Tribes of the North-West Coast of Borneo, by Lord Bishop of Labuan (1863) - Pasted Graphic 2.pdf.

The Lord Bishop also confirms the practice of secret languages among the Sea Dayaks - Pasted Graphic 3.pdf.

In The Relations Between Men and Animals in Sarawak, by Charles Hose; W. McDougall (1901) the authors confirm that the Iban have a lot of contact with the Malays and that this contact has influenced their belief system - Pasted Graphic 4.pdf.
They also give another reason why maybe an Iban would like to have something from a sea cow as a hilt and why it is so rare to see it - Pasted Graphic 5.pdf.

Michael