Conjoined twins in various animals, including humans, are uncommon but not unheard of. In some animals, however, this phenomena has never been observed. I’ve never heard of a real two headed elephant, for example. Until now, neither had I ever seen a two-headed deer.
In May 2016, a Minnesota man was hunting for mushrooms in a forest near the Mississippi River when he stumbled upon something a little more unusual than fungi. Nestled dead in the underbrush was what looked like a single newborn baby fawn, carrying two heads on one body.
A two-headed white-tailed fawn found two years ago in a Minnesota forest is cementing its place as a landmark case among the oddities found in nature.
According to a recently published study by researchers connected to the Minnesota DNR, the fawn is the first recorded case of a conjoined two-headed deer brought to full-term and born. There have only been two other cases of conjoined twins in white-tailed deer, neither made it through the full pregnancy.
“It’s never been described before,” said Lou Cornicelli, a co-author on the study and a wildlife research manager for the DNR. “There are a few reported cases of two-headed ungulate fetuses, but nothing delivered to term. So, the uniqueness made it special.”
In May 2016, a mushroom hunter found the two-headed fawn “freshly dead” in the forest near Freeborn in Houston County. For the researchers, finding such a unique creature in such good condition was a boon.
“Animals that are stillborn, they don’t last long on the landscape because of scavengers,” said Cornicelli. “In our case, we were lucky that he found the fawn before it was eaten and turned it into DNR.”
After testing the fawn’s lungs, the researchers confirmed the fawn was stillborn. X-rays showed it had two separate head-neck regions, which rejoined along the spine. A full necropsy detailed various internal issues, explaining why the little fawn’s life ended so soon. But it still remains unclear how exactly the creature came to be.
Wild Images In Motion Taxidermy mounted the unique two-headed fawn on a bed of greenery, where it lies as though it is just waking from a nap. The mount will eventually be moved to the MNDNR headquarters in St. Paul, where it will be on public display.
“We all thought it was pretty neat and were glad to be able to show it to the public,” said Cornicelli. “The taxidermists, Robert Utne and Jessica Brooks did a great job with the mount and treated it very respectfully.”
In case you thought it might just be the angle of the photo, here is a different view and a CT scan from the Independent.
The skeleton of the conjoined fawns was revealed by a CT scan (University of Georgia)
What causes coinjoined twins?
Conjoined twins are identical twins joined in utero. An extremely rare phenomenon, the occurrence is estimated to range from 1 in 49,000 births to 1 in 189,000 births, with a somewhat higher incidence in Southeast Asia and Africa. Approximately half are stillborn, and an additional one-third die within 24 hours. Most live births are female, with a ratio of 3:1.
Two contradicting theories exist to explain the origins of conjoined twins. The more generally accepted theory is fission, in which the fertilized egg splits partially. The other theory, no longer believed to be the basis of conjoined twinning, is fusion, in which a fertilized egg completely separates, but stem cells (which search for similar cells) find similar stem cells on the other twin and fuse the twins together. Conjoined twins share a single common chorion, placenta, and amniotic sac, although these characteristics are not exclusive to conjoined twins, as there are some monozygotic but non-conjoined twins who also share these structures in utero.
Conjoined twinning occurs by the incomplete splitting of the embryonic axis and, with the exception of parasitic conjoined twins, all are symmetrical and “the same parts are always united to the same parts”. Fusion of monozygotic twins is no longer believed to be the basis of conjoined twinning.” Nandesuka 01:02, 18 December 2005 (UTC)
If conjoined twins are caused by incomplete splitting of the embryonic axis, what might cause this during development? Science has some good clues.
Conjoined twinning … only arises when the twinning event occurs at about the primitive streak stage of development, at about 13–14 days after fertilisation in the human, and is exclusively associated with the monoamniotic monochorionic type of placentation. It is believed that the highest incidence of conjoined twinning is encountered in the human. While monozygotic twinning may be induced experimentally following exposure to a variety of agents, the mechanism of induction of spontaneous twinning in the human remains unknown. All agents that are capable of acting as a twinning stimulus are teratogenic, and probably act by interfering with the spindle apparatus.
Teratogenic means “a drug or other substance capable of interfering with the development of a fetus, causing birth defects.” There is a long list of substances which can cause developmental errors and a good guess would be that the mother deer who had these conjoined fawns was exposed to something toxic there in Minnesota.
Teratogen: Any agent that can disturb the development of an embryo or fetus. Teratogens may cause a birth defect in the child. Or a teratogen may halt the pregnancy outright. The classes of teratogens include radiation, maternal infections, chemicals, and drugs.
… Drugs known to be capable of acting as teratogens include, but are by no means limited to, ACE inhibitors like benazepril (brand name: Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril sodium (Monopril), lisinopril (Zestril, Prinivil), lisinopril and hydrochlorothiazide (Zestoretic, Prinzide), quinapril (Accupril), and ramipril (Altace); the acne medication isotretinoin (Accutane, Retin-A); alcohol, whether ingested chronically or in binges; androgens (male hormones); the antibiotics tetracycline (Achromycin), doxycycline (Vibramycin), and streptomycin; blood-thinners, such as warfarin (Coumadin); seizure medications, including phenytoin (Dilantin), valproic acid (Depakene, Depakote, Valprotate), trimethadione (Tridione), paramethadione (Paradione), and carbamazepine (Tegretol); the anti- depressant/anti-manic drug lithium (Eskalith, Lithotab); …
How many of these chemicals are in the water sources a Minnesota deer may use?
A cornucopia of man-made chemicals — including cocaine, DEET, synthetic estrogen, antibiotics, antidepressants and plastics derivatives — are finding their way into even isolated Minnesota lakes, an indication that some contamination is becoming the norm for virtually all the state’s waters.
The other part of understanding how we can get a two headed deer is understanding on a basic level, how cells divide and how suseptible the delecate spindle apparatus is to disruption. It is amazing that it works at all, actually. Cell division, at the level of deeper details, is something that seems impossible or at least highly improbable, but happens nevertheless, luckily for us.
It is useful from time to time to recall fact that every one of us started as a single fertilized egg cell. Wild, isn’t it? This image below is a person, a human being, or will be if the amazing dance of atomic forces plays out as it has the potential to do, given the right environment.
You don’t remember being a single cell? That begs the question: what about consciousness, where does that come in? It helps to get clear on what you mean by consciousness. It may seem obvious, but it isn’t. Are you aware of your right foot right now? You weren’t, but now you are. Consciousness obviously has a filtering component to keep us focused on details which may assist our current biological quest.
Self-awareness, reaction to stimuli, awareness of the awareness of others, mindfulness instead of automation, freedom of choice, awareness of mortality, moral reasoning, the ability to learn, experiencing emotions … there are many definitions of consciousness.
I like to think of consciousness as “what it is like to have your particular mental model of the world,” meaning it is not really one thing, but a conglomeration of various features and available functions with an illusion of “self” of a single “being” experience. At least that’s how I saw it for a long time at the level of neurobiology.
I could be very wrong about that if the universe is a simulation. In that case, none of us may exist outside of it, or we may as something else… there are many more options. All of the biology we are discovering and examining, for example, could be “set dressing” that gets created in response to our looking at it. Sometimes it seems that crazy. What if “seek and you will find,” with some protections built in, is the truth of it all? Fun to consider.